1966 Cadillac Eldorado Spark Plugs

Keep Your 1966 Cadillac Eldorado in Top Shape with Quality Spark Plugs

Whether you’re repairing or upgrading your Spark Plug, using high-quality parts is key to keeping your 1966 Cadillac Eldorado looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Spark Plug Wire Set Cut To Fits and Spark Plugs. Whether you’re replacing a damaged part or enhancing your truck’s style and protection, you’ll find exactly what you need to get the job done right.

Top-Rated Spark Plugs from Trusted Brands

Looking for a reliable Spark Plug? We’ve got you covered with options from brands you know and trust like Champion, NGK, and Autolite. For example, Champion Spark Plugs start at just $3.79 with an average 4.7 star rating. NGK and Autolite offer similar pricing and quality, backed by strong customer feedback. With over 82 reviews and a solid 5 star average, you can shop with confidence knowing other Cadillac Eldorado owners approve.

Competitive Prices and Extensive Inventory

The average price for a 1966 Cadillac Eldorado Spark Plug at Advance Auto Parts is around $20.80, with a range that starts at $3.79 and goes up to $99.99. With 15 options in stock from 7 trusted brands, finding the right fit is easy. Popular picks like Copper Core Spark Plug: Reliable Performance & Durability, DiamondFIRE Spark Plug: More Power & Fuel Efficiency, and V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance start at just $6.29 and offer a great balance of form and function.

Explore Related Parts

While you’re upgrading or replacing your Spark Plug, don’t forget to check out other key components like Ignition Boots and Ignition Coils and Boots. At Advance Auto Parts, we’re here to help you keep your 1966 Cadillac Eldorado in peak condition, inside and out.

Essential 1966 Cadillac Eldorado Spark Plugs

Accel – 8Mm Super Stock Graphite Uni (Part No.4040B)

8Mm Super Stock Graphite Uni

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$71.99
ACCEL’s SuperStock 4000 series spark plug wire sets are designed to upgrade an OE ignition system for high-spark delivery levels for street driven applications. The 450 degree F rated silicone jacket is extruded over a tightly woven, rugged fiberglass braid. The braid is applied over high dielectric strength EPDM (Ethylene Propylene Diene Monomer) inner insulation for ignition wire performance that exceeds SAE specifications.

Product Features:
  • 7mm And 8mm High Gloss Silicone Jacket
  • 450 F Rated Silicone Jacket
  • Stainless Steel Plug Terminals
  • RFI Suppression For Street Driven Applications
  • Custom-fit Universal And Import Coverage
  • High-strength Fiberglass Braid Construction
  • Pre And Post HEI Vehicles
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Accel – 8Mm Super Stock Spiral Uni Bk (Part No.5040K)

8Mm Super Stock Spiral Uni Bk

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$99.99
The traditional ACCEL combination of yellow wire and red spark plug boots has been added to these SuperStock Spiral Core 5000 Series wire sets, which feature color-matched wire and spark plug boots in blue, black, and red. With only 500 ohms/ft. of resistance, more ignition energy can reach the spark plug, producing a longer-lasting, hotter spark flame kernel. The results is higher performance through improved efficiency, quicker throttle response, and reduced emissions. This 8mm wire’s double silicone construction is rated to 550 degrees F. The high-gloss wire jacket resists moisture, chemicals, and heat extremes for longer life and great looks. The fiberglass braid adds greater pull strength and terminal retention, while the stainless steel spark plug terminals provide excellent long life, electrical conductivity, and corrosion resistance. Both universal and custom-fit applications are available for early and late model cars and trucks.

Product Features:
  • 500 Ohms/ft Of Resistance
  • 550 F Rated Silicone Jacket
  • Stainless Steel Plug Terminals
  • High RFI Suppression For Street And Strip Use
  • Universal And Import Coverage
  • High-strength Fiberglass Braid Construction
  • Pre And Post HEI Vehicles
  • 8mm High Gloss Silicone Jacket
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Autolite – Copper Resistor Spark Plug: Quick Starts & Enhanced Durability (Part No.666)

Copper Resistor Spark Plug: Quick Starts & Enhanced Durability

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$3.99
Autolite Copper spark plugs are expertly crafted to ensure reliable performance and durability for your vehicle. Featuring a copper core center electrode, these spark plugs excel in thermal control and resist fouling, ensuring consistent operation. The high nickel alloy center and ground electrodes are designed for extended life, while the nickel-plated shell offers superior corrosion resistance for long-lasting durability. With a high alumina multi-rib ceramic insulator, these spark plugs provide excellent thermal conductivity and insulation, enhancing strength and reliability. Engineered with a mid-projection standard center electrode and tapered seat type, they deliver optimal compatibility and performance. The nickel tip material on both the center and ground electrodes ensures robust functionality, while the built-in resistor type further enhances efficiency. Designed to optimize fuel economy, these spark plugs help you save on fuel costs without compromising on power or quick starts. Perfect for regular-grade applications, they are a dependable choice for maintaining peak engine performance.

Product Features:
  • The copper core center electrode aids in thermal control and improves resistance to fouling.
  • Its specially engineered high nickel alloy center and ground electrode provides extended life.
  • The high alumina multi-rib ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended periods.
  • Good Fuel Economy: Engineered to optimize fuel efficiency, helping you save on fuel costs.
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Champion – Copper Plus Spark Plug (RS12YC): Dependable Performance & Durability (Part No.401)

Copper Plus Spark Plug (RS12YC): Dependable Performance & Durability

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$2.99
The Copper Plus Spark Plug delivers dependable performance and durability, making it a reliable choice for maintaining optimal engine function. Featuring a copper core center electrode, it ensures enhanced conductivity and precise heat control, promoting good overall wear and extending the spark plug’s lifespan. Built to ISO and SAE Standards, this spark plug guarantees proven performance and superior corrosion resistance, even in demanding conditions. Its nickel center electrode tip and tapered seat design further enhance reliability and engine efficiency, making it an excellent standard replacement option. With a resistor type design and robust materials, this spark plug is engineered to provide consistent ignition and long-lasting durability, ensuring your vehicle runs smoothly mile after mile.

Product Features:
  • Copper Plus – Dependable Performance and Durability
  • Copper core center electrode allows for accurate control of heat range for longer life
  • Superior corrosion resistance
  • Built to ISO and SAE standards for proven performance
  • Built to ISO and SAE standards for proven performance
  • Enhanced Conductivity and Heat Control: The Champion Copper Plus Spark Plug features a copper core electrode that provides increased conductivity and heat control, ensuring good overall wear and extending the spark plug’s life.
  • Reliable Nickel Center Electrode Tip: Featuring a nickel center electrode tip and a tapered seat type, this spark plug enhances reliability and ensures optimal engine performance.
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Champion – Iridium Spark Plug (RS8WYPB5): Maximum Performance & Longevity (Part No.9808)

Iridium Spark Plug (RS8WYPB5): Maximum Performance & Longevity

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$8.49
The Champion Iridium Spark Plug is engineered for maximum performance and longevity, making it a premium choice for your vehicle. Featuring a fine-wire iridium center electrode and a V-trimmed iridium-platinum ground electrode, this spark plug ensures sharper spark focus and greater ignitability for optimal engine efficiency. Its Heat-Active alloy allows the electrodes to quickly reach and maintain stable operating temperatures under all engine loads, ensuring consistent performance. Designed with a tapered seat and built-in resistor, it delivers reliable operation while reducing interference. The iridium center electrode is crafted for maximum durability and extended life, making it ideal for high-performance applications. Whether you’re looking to enhance your vehicle’s ignition system or maintain peak engine performance, this spark plug offers exceptional value and reliability.

Product Features:
  • Champion Iridium – Maximum Performance. Premium Spark Plug
  • Iridium center electrode delivers maximum life
  • Fine-wire center electrode and V-trimmed for greater ignitability
  • V-trimmed ground electrode promotes sharper spark focus
  • Maintains stable operating temperature under all engine loads
  • Heat-Active alloy allows electrodes to reach optimal temperature quickly
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DENSO – U-Groove Spark Plug: OE Performance, W16EXR-U (Part No.3031)

U-Groove Spark Plug: OE Performance, W16EXR-U

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$3.29
The U-Groove Spark Plug with its patented U-groove ground electrode design ensures superior ignitability, allowing your engine to fire leaner mixtures for enhanced efficiency and performance. Crafted with precision machine-rolled threads, it minimizes the risk of seizing or cross-threading, making it ideal for delicate aluminum heads. Built to last twice as long as conventional plugs, this spark plug is 100% pre-fired to guarantee reliable operation from the start. Its nickel center electrode tip and flat seat type ensure consistent performance across a wide range of applications, including classic and collector cars. With a comprehensive selection of part numbers available, this spark plug delivers OE-level performance and durability, making it a dependable choice for maintaining your engine’s peak performance.

Product Features:
  • Patented U-groove ground electrode design fires leaner mixtures than conventional plugs
  • Precision machine-rolled threads reduce seizing and cross-threading in delicate aluminum heads
  • Wide range of part numbers for thousands of applications, including classic and collector cars
  • Lasts twice as long as most conventional plugs
  • 100 percent pre-fired to assure reliable operation
  • U-Groove Conventional
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Autolite – Double Platinum Spark Plug: Enhanced Durability & Performance (Part No.APP605)

Double Platinum Spark Plug: Enhanced Durability & Performance

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$6.99
The Double Platinum Spark Plug is engineered for exceptional durability and performance, making it a top choice for distributor-less ignition system (DIS) engines. Featuring a platinum-to-platinum design, it minimizes gap erosion and reduces misfires, ensuring a longer service life compared to copper and standard platinum plugs. Its yttrium-enhanced ground electrode delivers superior heat transfer, maintaining durability under high temperatures and pressure. The high alumina ceramic insulator optimizes thermal conductivity and dielectric strength, while the multi-rib insulator prevents flash-over for reliable operation. With a mid-projection center electrode and tapered seat type, this performance-grade spark plug is built to handle demanding conditions. Both the center and ground electrode tips are crafted from platinum, ensuring consistent ignition and enhanced efficiency. Designed to deliver value and reliability, this spark plug is a smart upgrade for those seeking improved engine performance and longevity.

Product Features:
  • Engineered with a platinum-to-platinum design that prevents gap erosion, extending the life of the spark plug.
  • The yttrium-Enhanced Ground Electrode delivers superior heat transfer that delivers more durability under high temps and pressure for greater life.
  • Its high alumina ceramic insulator provides optimum thermal conductivity and dielectric strength.
  • The multi-rib insulator prevents flash-over.
  • Crafted with a mid-projection center electrode and tapered seat type, this spark plug is designed to handle demanding conditions, ensuring reliable performance and efficiency.
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ACDelco – RAPIDFIRE Platinum Spark Plug: Reduces Misfires & Enhances Durability (Part No.2)

RAPIDFIRE Platinum Spark Plug: Reduces Misfires & Enhances Durability

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$6.99
ACDelco Gold (Professional) RAPIDFIRE Spark Plugs are a high quality alternative to Original Equipment (OE) parts. These RAPIDFIRE Single Platinum Performance Spark Plugs are designed for everyday use and are a high quality replacement for many vehicles on the road today. These premium aftermarket spark plugs have high-quality suppressors that help prevent misfiring, an improved plug to boot seal, and a pure copper core for greater durability. These premium aftermarket replacement spark plugs are manufactured to meet your expectations for fit, form, and function. ACDelco Gold (Professional) parts are manufactured to meet your expectations for fit, form, and function, making them a smart choice for General Motors vehicles, as well as most makes and models, including special applications. These high-quality parts are backed by General Motors. Some ACDelco Gold parts may have formerly appeared as ACDelco Professional.

Product Features:
  • Solid state suppressor, with two-piece glass and brass seal, can help reduce radio frequency interference, regulates spark energy for long electrode life, and helps protect against high combustion pressures
  • Pure copper core provides great heat transfer and helps maximize plug durability
  • Platinum on center electrode enables superior spark characteristics and can reduce voltage requirements of the ignition system
  • Ribless insulator helps optimize plug to boot seal
  • Some ACDelco Gold parts may have formerly appeared as ACDelco Professional
  • Premium aftermarket replacement part
  • Manufactured to meet specifications for fit, form, and function for General Motors vehicles as well as most makes and models
  • High-Quality Suppressors: ACDelco Gold RAPIDFIRE Spark Plugs feature high-quality suppressors that help prevent misfiring, ensuring reliable performance for everyday use.
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Autolite – Platinum Spark Plug (AP666): Enhanced Durability & Performance (Part No.AP666)

Platinum Spark Plug (AP666): Enhanced Durability & Performance

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$4.99
The Platinum Spark Plug (AP666) is a high-performance solution designed to elevate your engine’s efficiency and reliability. Featuring a platinum center electrode firing tip, it ensures quicker firing, smoother starts, and improved fuel efficiency while preventing gap erosion for a longer service life. Its high alumina ceramic insulator enhances thermal conductivity and insulation, delivering superior strength under demanding conditions. The multi-rib insulator effectively prevents flash-over, while the nickel-plated shell resists corrosion, ensuring extended durability. With a mid-projection center electrode and tapered seat type, this spark plug is tailored for optimal performance in older engine applications and designs. The combination of platinum and nickel materials in the electrode tips guarantees consistent ignition and robust performance, making it a dependable choice for drivers seeking enhanced acceleration and reliability. Engineered for durability and efficiency, this spark plug is a smart investment for maintaining peak engine performance over time.

Product Features:
  • Engineered with a platinum firing tip that prevents gap erosion for longer service life.
  • Its high alumina ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • The multi-rib insulator prevents flash-over.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended life.
  • Tailored with a mid-projection center electrode and tapered seat type, this spark plug is optimized for older engine designs, ensuring consistent ignition and reliable performance.
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Autolite – Platinum Spark Plug: Enhanced Durability & Fuel Efficiency (Part No.AP104)

Platinum Spark Plug: Enhanced Durability & Fuel Efficiency

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$4.99
Autolite Platinum spark plugs are crafted for exceptional performance and durability, making them ideal for older engine applications. Featuring a platinum center electrode firing tip, these spark plugs ensure quicker firing, smoother starts, and enhanced acceleration while boosting fuel efficiency. The platinum firing tip prevents gap erosion, extending the service life, while the high alumina ceramic insulator offers superior thermal conductivity and insulation for added strength. A multi-rib insulator design prevents flash-over, ensuring reliable operation, and the nickel-plated shell resists corrosion for long-lasting durability. With a mid-projection standard center electrode and a tapered seat type, these performance-grade spark plugs deliver consistent results. The combination of platinum and nickel materials in the electrode tips further enhances reliability, making them a smart choice for drivers seeking improved engine efficiency and extended part longevity.

Product Features:
  • Engineered with a platinum firing tip that prevents gap erosion for longer service life.
  • Its high alumina ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • The multi-rib insulator prevents flash-over.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended life.
  • Incorporates a mid-projection standard center electrode design to ensure consistent performance and reliable ignition in a variety of engine conditions.
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NGK – V-Power Nickel Spark Plug (UR45): Reliable Performance & Ignitability (Part No.6945)

V-Power Nickel Spark Plug (UR45): Reliable Performance & Ignitability

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$6.99
NGK V-Power spark plugs offer reliable performance and improved ignitability over standard nickel plugs. Engineered specifically for OE applications, the special V-cut nickel alloy center electrode and concave ground electrode of NGK’s V-Power spark plug increases ignitability providing quicker starts and smoother idle. NGK’s legendary high grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance. Trivalent metal plating ensures superior anti-corrosion and anti-seizing properties.

Product Features:
  • ACTUAL OE or EQUIVALENT DESIGN: OEM quality construction nickel alloy center electrode with V-groove provides consistent performance
  • RECOMMENDED USAGE: Best for vehicles with OE nickel alloy plugs, not recommended on vehicles with factory precious metal plugs
  • NGK’s OE CERAMIC TECHNOLOGY: High grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance
  • SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
  • COLD-ROLLED THREADS: Prevents cross-threading and damage to cylinder heads
  • TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal
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Motorcraft – Spark Plug: Reliable Ignition & Engine Efficiency (Part No.SP-423-A)

Spark Plug: Reliable Ignition & Engine Efficiency

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$2.99
Ensure your engine runs smoothly and efficiently with this high-quality spark plug, designed to deliver reliable ignition and optimal performance. Built to withstand extreme conditions, it provides consistent combustion for improved fuel efficiency and reduced emissions. Its durable construction ensures long-lasting performance, making it a dependable choice for maintaining your vehicle’s engine health. Engineered for compatibility with a wide range of vehicles, this spark plug is easy to install and helps restore peak engine performance. Whether you’re replacing a worn-out plug or performing routine maintenance, this spark plug offers exceptional value and reliability for your automotive needs.

Product Features:
  • Designed to deliver reliable ignition for consistent engine start-up and performance.
  • Optimized for improved fuel efficiency, helping reduce overall fuel consumption.
  • Built to withstand extreme conditions, ensuring durability and long-lasting use.
  • Easy to install, making routine maintenance or replacement hassle-free.
  • Engineered for compatibility with a wide range of vehicles, offering versatile application.
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Champion – Copper Plus Spark Plug (RN14YC): Dependable Performance & Durability (Part No.405)

Copper Plus Spark Plug (RN14YC): Dependable Performance & Durability

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$4.99
The Copper Plus spark plug delivers dependable performance and durability, making it an ideal choice for maintaining your engine’s efficiency. Featuring a copper core center electrode, it ensures precise heat control for extended lifespan and consistent wear. Its nickel center electrode tip and flat seat design enhance reliability while meeting ISO and SAE Standards for proven performance. Built with superior corrosion resistance, this spark plug is designed to withstand harsh conditions, ensuring long-term functionality. As a standard replacement grade type with a resistor, it offers compatibility with a wide range of vehicles. Whether you’re looking for improved conductivity or reliable ignition, this spark plug provides excellent value and performance for your engine’s needs.

Product Features:
  • Copper Plus – Dependable Performance and Durability
  • Copper core center electrode allows for accurate control of heat range for longer life
  • Superior corrosion resistance
  • Built to ISO and SAE standards for proven performance
  • Built to ISO and SAE standards for proven performance
  • Reliable Nickel Center Electrode Tip: Featuring a nickel center electrode tip and flat seat type, this spark plug enhances reliability and helps maintain your engine’s efficiency.
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Autolite Iridium – Iridium XP Fine wire Spark Plug: Improved Durability, More Focused Ignition (Part No.XP605)

Iridium XP Fine wire Spark Plug: Improved Durability, More Focused Ignition

from

$10.99
Autolite has over 100 years of engineering experience and has sold over 11 billion plugs. Designed and engineered in the USA, the Autolite Iridium XP spark plugs feature an iridium-enhanced 0.6mm finewire design and patented platinum sidewire technology to provide better overall durability and a more focused ignition for enhanced ignitability and performance. Features double Iridium-enhanced alloy technology center electrode for improved durability and wear resistance.

Product Features:
  • 0.6 mm finewire design improves ignitability
  • Patented V-trimmed platinum sidewire technology resists wear
  • OE equivalent design is engineered for every engine
  • Designed for better overall durability with virtually no gap erosion
  • Double Iridium-Enhanced Alloy Technology Center Electrode: Offers improved durability and wear resistance.
  • Designed and Engineered in the USA: Reflects over 100 years of Autolite’s engineering experience.
  • Tapered Seat Type: Ensures a secure fit and optimal performance in compatible engines.
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Autolite Iridium – Iridium XP Fine wire Spark Plug: Improved Durability, More Focused Ignition (Part No.XP104)

Iridium XP Fine wire Spark Plug: Improved Durability, More Focused Ignition

from

$10.99
Autolite has over 100 years of engineering experience and has sold over 11 billion plugs. Designed and engineered in the USA, the Autolite Iridium XP spark plugs feature an iridium-enhanced 0.6mm finewire design and patented platinum sidewire technology to provide better overall durability and a more focused ignition for enhanced ignitability and performance. Features double Iridium-enhanced alloy technology center electrode for improved durability and wear resistance.

Product Features:
  • 0.6 mm finewire design improves ignitability
  • Patented V-trimmed platinum sidewire technology resists wear
  • OE equivalent design is engineered for every engine
  • Designed for better overall durability with virtually no gap erosion
  • Double Iridium-enhanced alloy technology ensures superior wear resistance for extended plug life.
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Motorcraft – Double Platinum Spark Plug: Enhances Durability & Reduces Misfires (Part No.SP-486)

Double Platinum Spark Plug: Enhances Durability & Reduces Misfires

from

$7.29
Motorcraft Spark Plugs are original equipment on Ford Motor Company vehicles, engineered to meet strict Ford engineering standards for performance and reliability. These spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption, and optimize emissions. With a platinum center and ground electrode tip, they are resistant to oxidation and arc erosion, ensuring long-lasting performance. The multi-rib insulator protects against misfire, and they are backed by Motorcraft’s Service Parts Warranty. Designed for exact fit in Ford, Lincoln, and Mercury vehicles, they also help prevent false check engine lights. With service intervals of up to 100,000 miles, Motorcraft Spark Plugs are crafted from high-quality materials to deliver reliable performance for almost any application, making them the same components that were in the vehicle when it was manufactured.

Product Features:
  • Motorcraft spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption and optimize emissions.
  • Backed by Motorcraft’s Service Parts Warranty
  • Exact fit for Ford, Lincoln and Mercury vehicles
  • Resistant to oxidation and arc erosion.
  • Multi-rib insulator protects against misfire.
  • Service intervals of up to 100,000 miles.
  • Motorcraft Spark Plugs are designed with high quality materials to provide reliable performance for almost any application.
  • Motorcraft Spark Plugs are what was in the vehicle when it was manufactured
  • Motorcraft ignition components help prevent false check engine lights.
  • Enhanced Durability: Engineered with a platinum center and ground electrode tip, these spark plugs are resistant to oxidation and arc erosion, ensuring long-lasting performance.
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Champion – Platinum Power Spark Plug (RS14PYC6): Powerful Performance & Durability (Part No.3013)

Platinum Power Spark Plug (RS14PYC6): Powerful Performance & Durability

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$4.99
Champion Platinum Power spark plugs are engineered for exceptional performance and durability, making them an ideal choice for maintaining peak engine efficiency. Featuring a platinum center electrode, these spark plugs ensure long-lasting reliability and consistent performance. The fine-wire center electrode enhances ignitability, while the V-trimmed ground electrode sharpens spark focus for optimal combustion. Constructed with Heat-Active alloy, the electrodes quickly reach and maintain the ideal operating temperature, ensuring smooth engine operation under various conditions. The platinum-tipped center wire resists wear and helps maintain the proper gap specification throughout the life of the plug, reducing the need for frequent replacements. Designed as a standard replacement with a tapered seat type, these spark plugs are built to meet or exceed OEM Standards. With a nickel ground electrode tip and integrated resistor, they deliver dependable performance and value, making them a smart investment for your vehicle’s ignition system.

Product Features:
  • Platinum Power- Premium Spark Plug. Powerful Performance.
  • Platinum center electrode for long life
  • Fine-wire center electrode for greater ignitability
  • V-trimmed ground electrode promotes sharper spark focus
  • Heat-Active alloy allows electrodes to reach optimal temperature
  • Platinum tipped center wire resists wear and helps to maintain proper gap spec over life of the plug
  • Platinum Center Electrode: Features a platinum center electrode for extended durability and long life.
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Autolite Iridium – Iridium XP Fine wire Spark Plug: Improved Durability, More Focused Ignition (Part No.XP64)

Iridium XP Fine wire Spark Plug: Improved Durability, More Focused Ignition

from

$9.99
Autolite has over 100 years of engineering experience and has sold over 11 billion plugs. Designed and engineered in the USA, the Autolite Iridium XP spark plugs feature an iridium-enhanced 0.6mm finewire design and patented platinum sidewire technology to provide better overall durability and a more focused ignition for enhanced ignitability and performance. Features double Iridium-enhanced alloy technology center electrode for improved durability and wear resistance.

Product Features:
  • 0.6 mm finewire design improves ignitability
  • Patented V-trimmed platinum sidewire technology resists wear
  • OE equivalent design is engineered for every engine
  • Designed for better overall durability with virtually no gap erosion
  • Double Iridium-enhanced alloy center electrode ensures superior wear resistance for extended performance life.
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Motorcraft – Standard Spark Plug: Reliable Performance & Durability (Part No.SP-447)

Standard Spark Plug: Reliable Performance & Durability

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$4.79
Standard Spark Plug by Motorcraft delivers reliable performance and durability, making it the ideal choice for Ford, Lincoln, and Mercury vehicles. Engineered to meet strict Ford standards, these spark plugs ensure original equipment performance while enhancing durability, reducing misfires, optimizing emissions, and improving fuel efficiency. Designed with high-quality materials, they resist oxidation and arc erosion, while the multi-rib insulator protects against misfires for consistent ignition. With service intervals of up to 100,000 miles, these spark plugs provide long-lasting reliability and confidence on the road. Backed by Motorcraft’s Service Parts Warranty, they are an exact fit for your vehicle and help prevent false check engine lights, ensuring peace of mind. Whether for domestic or import cars and trucks, Motorcraft spark plugs are the trusted solution for maintaining peak engine performance.

Product Features:
  • Motorcraft spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption and optimize emissions.
  • Backed by Motorcraft’s Service Parts Warranty
  • Exact fit for Ford, Lincoln and Mercury vehicles
  • Resistant to oxidation and arc erosion.
  • Multi-rib insulator protects against misfire.
  • Service intervals of up to 100,000 miles.
  • Motorcraft Spark Plugs are designed with high quality materials to provide reliable performance for almost any application.
  • Motorcraft Spark Plugs are what was in the vehicle when it was manufactured
  • Motorcraft ignition components help prevent false check engine lights.
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Motorcraft – Iridium Spark Plug: Enhances Durability & Reduces Fuel Consumption (Part No.SP-541-A)

Iridium Spark Plug: Enhances Durability & Reduces Fuel Consumption

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$13.49
Motorcraft Spark Plugs are original equipment on Ford Motor Company vehicles, engineered to meet strict Ford engineering standards for performance and reliability. These spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption, and optimize emissions. Backed by Motorcraft’s Service Parts Warranty, they are an exact fit for Ford, Lincoln, and Mercury vehicles and are resistant to oxidation and arc erosion. The multi-rib insulator protects against misfire, and they offer service intervals of up to 100,000 miles. Designed with high-quality materials, Motorcraft Spark Plugs provide reliable performance for almost any application and help prevent false check engine lights. With platinum center and ground electrode tips, these spark plugs ensure your vehicle runs as it did when it was first manufactured.

Product Features:
  • Motorcraft spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption and optimize emissions.
  • Backed by Motorcraft’s Service Parts Warranty
  • Exact fit for Ford, Lincoln and Mercury vehicles
  • Resistant to oxidation and arc erosion.
  • Multi-rib insulator protects against misfire.
  • Service intervals of up to 100,000 miles.
  • Motorcraft Spark Plugs are designed with high quality materials to provide reliable performance for almost any application.
  • Motorcraft Spark Plugs are what was in the vehicle when it was manufactured
  • Motorcraft ignition components help prevent false check engine lights.
  • Enhanced Durability: Engineered to meet strict Ford engineering standards, these Motorcraft Iridium Spark Plugs are designed to provide enhanced durability and long-lasting performance.
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Champion – Double Platinum Power Spark Plug (RS12PYP): Enhanced Durability & Performance (Part No.7401)

Double Platinum Power Spark Plug (RS12PYP): Enhanced Durability & Performance

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$4.99
Champion Double Platinum Power spark plugs are engineered for enhanced durability and performance, making them a premium choice for reliable ignition. Featuring a platinum fine-wire center electrode and platinum pad ground electrode, these spark plugs deliver greater wear resistance and sharper spark focus for consistent ignitability. The V-trimmed ground electrode ensures precise spark delivery, while the exclusive Heat-Active alloy optimizes electrode temperature under all engine loads, maintaining stable operation. Designed as a standard replacement, these spark plugs are equipped with a tapered seat and resistor type for seamless compatibility with a wide range of vehicles. Whether you’re seeking improved engine efficiency or long-lasting performance, Champion Double Platinum Power spark plugs provide exceptional value with their advanced materials and innovative design.

Product Features:
  • Double Platinum Power – Premium Spark Plug. More Powerful Performance.
  • Platinum center and ground electrode for greater wear resistance
  • Maintains stable operating temperature under all engine loads
  • Fine-wire center electrode for greater ignitability
  • V-trimmed ground electrode promotes sharper spark focus
  • Heat-Active alloy allows electrodes to reach optimal temperature
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Autolite – Copper Resistor Spark Plug: Quick Starts & Enhanced Durability (Part No.646)

Copper Resistor Spark Plug: Quick Starts & Enhanced Durability

from

$3.99
Autolite Copper spark plugs are designed to provide reliable performance and durability for your vehicle. Featuring a copper core center electrode, these spark plugs excel in thermal control and resist fouling, ensuring consistent operation. The high nickel alloy center and ground electrodes are engineered for extended life, while the mid-projection design optimizes spark delivery. A high alumina multi-rib ceramic insulator enhances thermal conductivity and insulation, offering superior strength under demanding conditions. The nickel-plated shell resists corrosion, adding to the plug’s longevity. With a flat seat type and built-in resistor, these spark plugs are a dependable choice for maintaining quick starts and meeting your vehicle’s performance needs.

Product Features:
  • The copper core center electrode aids in thermal control and improves resistance to fouling.
  • Its specially engineered high nickel alloy center and ground electrode provides extended life.
  • The high alumina multi-rib ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended periods.
  • The mid-projection design of the center electrode ensures optimized spark delivery for consistent and efficient engine performance.
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Motorcraft – High-Performance Spark Plug: Enhances Fuel Efficiency (Part No.SP-541-AX)

High-Performance Spark Plug: Enhances Fuel Efficiency

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$14.99
The Motorcraft High-Performance Spark Plug is meticulously crafted to deliver superior ignition performance and optimize fuel efficiency, ensuring your vehicle operates at its best. Featuring a fine wire center electrode and platinum tips on both the center and ground electrodes, this spark plug is designed for exceptional durability and consistent performance. Its tapered seat type ensures a secure fit, contributing to reliable starts and smooth engine operation. Engineered to enhance fuel economy, it helps you maximize every gallon while maintaining peak vehicle performance over time. Trust Motorcraft’s commitment to quality and efficiency to keep your engine running smoothly, making this spark plug a valuable addition to your vehicle’s maintenance routine.

Product Features:
  • Optimizes Fuel Efficiency: The Motorcraft High-Performance Spark Plug is engineered to enhance fuel efficiency, helping you get the most out of every gallon.
  • Superior Ignition Performance: Designed for superior ignition performance, this spark plug ensures reliable starts every time you turn the key.
  • Exceptional Durability: Crafted with precision, the Motorcraft High-Performance Spark Plug offers exceptional durability, providing long-lasting performance.
  • Consistent Performance: This spark plug is designed to deliver consistent performance, maintaining your vehicle’s peak performance over time.
  • Trusted Quality: Trust Motorcraft to deliver quality and efficiency with every drive, ensuring your vehicle runs smoothly and efficiently.
  • Optimizes Fuel Efficiency: The Motorcraft High-Performance Spark Plug is engineered to enhance fuel efficiency, helping you get the most out of every gallon.
  • Superior Ignition Performance: Designed for superior ignition performance, this spark plug ensures reliable starts every time you turn the key.
  • Exceptional Durability: Crafted with precision, the Motorcraft High-Performance Spark Plug offers exceptional durability, providing long-lasting performance.
  • Consistent Performance: This spark plug is designed to deliver consistent performance, maintaining your vehicle’s peak performance over time.
  • Trusted Quality: Trust Motorcraft to deliver quality and efficiency with every drive, ensuring your vehicle runs smoothly and efficiently.
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ACDelco – RAPIDFIRE Platinum Spark Plug: Reduces Misfires & Enhances Durability (Part No.12)

RAPIDFIRE Platinum Spark Plug: Reduces Misfires & Enhances Durability

from

$6.99
ACDelco Gold (Professional) RAPIDFIRE Spark Plugs are a high quality alternative to Original Equipment (OE) parts. These RAPIDFIRE Single Platinum Performance Spark Plugs are designed for everyday use and are a high quality replacement for many vehicles on the road today. These premium aftermarket spark plugs have high-quality suppressors that help prevent misfiring, an improved plug to boot seal, and a pure copper core for greater durability. These premium aftermarket replacement spark plugs are manufactured to meet your expectations for fit, form, and function. ACDelco Gold (Professional) parts are manufactured to meet your expectations for fit, form, and function, making them a smart choice for General Motors vehicles, as well as most makes and models, including special applications. These high-quality parts are backed by General Motors. Some ACDelco Gold parts may have formerly appeared as ACDelco Professional.

Product Features:
  • Solid state suppressor, with two-piece glass and brass seal, can help reduce radio frequency interference, regulates spark energy for long electrode life, and helps protect against high combustion pressures
  • Pure copper core provides great heat transfer and helps maximize plug durability
  • Platinum on center electrode enables superior spark characteristics and can reduce voltage requirements of the ignition system
  • Ribless insulator helps optimize plug to boot seal
  • Some ACDelco Gold parts may have formerly appeared as ACDelco Professional
  • Premium aftermarket replacement part
  • Manufactured to meet specifications for fit, form, and function for General Motors vehicles as well as most makes and models
  • High-Quality Suppressors: Designed to help prevent misfiring, ensuring smooth and reliable engine performance.
  • Improved Plug to Boot Seal: Enhances the connection between the spark plug and the ignition system, reducing the risk of leaks and improving overall efficiency.
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NGK – Standard Nickel Spark Plug (BPR4ES): Reliable OE Performance (Part No.6578)

Standard Nickel Spark Plug (BPR4ES): Reliable OE Performance

from

$5.99
NGK Standard spark plugs (in the iconic NGK ‘yellow box’ packaging) are a proven OE cornerstone and technology customers have relied on for decades. Engineered specifically for OE applications, NGK Standard spark plugs provide OE quality nickel alloy reliable performance and design. NGK’s legendary high grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance, while triple gasket sealing prevents combustion gas leakage. Solid 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges. Trivalent metal plating ensures superior anti-corrosion and anti-seizing properties.

Product Features:
  • ACTUAL OE or EQUIVALENT DESIGN: OEM quality construction nickel alloy center electrode provides consistent performance
  • RECOMMENDED USAGE: Best for vehicles with OE nickel alloy plugs, not recommended on vehicles with factory precious metal plugs
  • NGK’s OE CERAMIC TECHNOLOGY: High grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance
  • SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
  • COLD-ROLLED THREADS: Prevents cross-threading and damage to cylinder heads
  • TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal
  • Triple Gasket Sealing: Prevents combustion gas leakage, ensuring efficient engine performance.
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Champion – Double Platinum Power Spark Plug (RS12PYPB5): Enhanced Durability & Performance (Part No.7963)

Double Platinum Power Spark Plug (RS12PYPB5): Enhanced Durability & Performance

from

$6.99
Champion Double Platinum Power spark plugs are engineered to deliver exceptional performance and durability for your vehicle. Featuring a fine-wire platinum center electrode and a platinum pad ground electrode, these spark plugs ensure greater wear resistance and sharper spark focus for reliable ignition. The innovative Heat-Active alloy allows the electrodes to maintain optimal operating temperatures under all engine loads, enhancing overall efficiency. With a V-trimmed ground electrode design, these plugs promote precise spark delivery, improving ignitability and engine performance. Designed as a standard replacement, they are built to provide maximum life and consistent performance, making them a dependable choice for maintaining your vehicle’s peak operation. Equipped with a resistor and a tapered seat type, these spark plugs are a perfect blend of advanced technology and practicality, ensuring stable performance and long-lasting reliability.

Product Features:
  • Double Platinum Power – Premium Spark Plug. More Powerful Performance.
  • Platinum center and ground electrode for greater wear resistance
  • Maintains stable operating temperature under all engine loads
  • Fine-wire center electrode for greater ignitability
  • V-trimmed ground electrode promotes sharper spark focus
  • Heat-Active alloy allows electrodes to reach optimal temperature
  • Platinum Center Electrode Tip: Guarantees maximum life and exceptional performance.
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ACDelco – Copper Core Spark Plug: Reliable Performance & Durability (Part No.R46SZ)

Copper Core Spark Plug: Reliable Performance & Durability

from

$6.29
ACDelco Professional Conventional Spark Plugs are designed for reliability and efficient performance, and are a high quality replacement for many vehicles on the road today. Their high-quality copper cores and outstanding suppression characteristics deliver reliable performance. They are also available for Marine applications. These premium aftermarket replacement spark plugs are manufactured to meet your expectations for fit, form, and function.

Product Features:
  • Black Onyx coating helps reduce corrosion
  • Copper core provides great heat transfer and helps maximize plug durability
  • Ribbed suppressor seal extends resistance and helps prevent spark ‘flash over’ and misfires
  • Nickel-chrome alloy sheathing helps prevent corrosion on center electrode
  • Available for use in Marine applications
  • Some ACDelco GM Original Equipment parts may have formerly appeared as GM Genuine Parts (OE) or ACDelco Professional
  • ACDelco GM Original Equipment parts are designed, engineered and tested to rigorous standards, and are backed by General Motors
  • GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle
  • GM regularly updates production and service part designs to integrate new materials and technologies
  • High-Quality Copper Core: ACDelco Professional Conventional Spark Plugs feature high-quality copper cores, ensuring reliable performance and efficient operation.
  • Nickel Center Electrode Tip: Designed with a nickel center electrode tip, these spark plugs provide durability and consistent performance.
  • Outstanding Suppression Characteristics: These spark plugs offer excellent suppression characteristics, contributing to their reliable performance in various driving conditions.
  • Premium Aftermarket Replacement: Manufactured to meet expectations for fit, form, and function, these spark plugs serve as a high-quality replacement for original equipment.
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ACDelco – Double Platinum Spark Plug: Long-Lasting Performance & Durability (Part No.41-950)

Double Platinum Spark Plug: Long-Lasting Performance & Durability

from

$10.99
ACDelco GM Original Equipment Double Platinum Spark Plugs are designed, engineered, and tested to rigorous standards, and are backed by General Motors. With a copper core and double platinum pads on the center electrode, these plugs are designed to deliver long-lasting performance. ACDelco GM Original Equipment parts are the true OE parts installed during the production or validated by General Motors for GM vehicles. Some ACDelco GM Original Equipment parts may have formerly appeared as GM Genuine Parts (OE) or ACDelco Professional.

Product Features:
  • One-piece, fired-in suppressor seal blends three glass types for a gas-tight seal that helps reduce radio frequency and engine interference, regulate spark plug energy, and protect against compression pressures for long life
  • Double platinum point pad on center and ground electrode offer excellent durability and consistent voltage demands to help reduce wear on ignition system
  • Some ACDelco GM Original Equipment parts may have formerly appeared as GM Genuine Parts (OE) or ACDelco Professional
  • ACDelco GM Original Equipment parts are designed, engineered and tested to rigorous standards, and are backed by General Motors
  • GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle
  • GM regularly updates production and service part designs to integrate new materials and technologies
  • Copper Core: Designed with a copper core to provide excellent heat transfer and electrical conductivity.
  • Conical Seat Type: Equipped with a conical seat type for a secure fit and optimal performance.
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Most Popular Spark Plug Wire Set Cut To Fits for 1966 Cadillac Eldorados

Enhance your 1966 Cadillac Eldorado with one of the 2 Spark Plug Wire Set Cut To Fits we have in stock, starting at just $71.99.

Accel – 8Mm Super Stock Graphite Uni (Part No.4040B)

8Mm Super Stock Graphite Uni

from

$71.99
ACCEL’s SuperStock 4000 series spark plug wire sets are designed to upgrade an OE ignition system for high-spark delivery levels for street driven applications. The 450 degree F rated silicone jacket is extruded over a tightly woven, rugged fiberglass braid. The braid is applied over high dielectric strength EPDM (Ethylene Propylene Diene Monomer) inner insulation for ignition wire performance that exceeds SAE specifications.

Product Features:
  • 7mm And 8mm High Gloss Silicone Jacket
  • 450 F Rated Silicone Jacket
  • Stainless Steel Plug Terminals
  • RFI Suppression For Street Driven Applications
  • Custom-fit Universal And Import Coverage
  • High-strength Fiberglass Braid Construction
  • Pre And Post HEI Vehicles
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Accel – 8Mm Super Stock Spiral Uni Bk (Part No.5040K)

8Mm Super Stock Spiral Uni Bk

from

$99.99
The traditional ACCEL combination of yellow wire and red spark plug boots has been added to these SuperStock Spiral Core 5000 Series wire sets, which feature color-matched wire and spark plug boots in blue, black, and red. With only 500 ohms/ft. of resistance, more ignition energy can reach the spark plug, producing a longer-lasting, hotter spark flame kernel. The results is higher performance through improved efficiency, quicker throttle response, and reduced emissions. This 8mm wire’s double silicone construction is rated to 550 degrees F. The high-gloss wire jacket resists moisture, chemicals, and heat extremes for longer life and great looks. The fiberglass braid adds greater pull strength and terminal retention, while the stainless steel spark plug terminals provide excellent long life, electrical conductivity, and corrosion resistance. Both universal and custom-fit applications are available for early and late model cars and trucks.

Product Features:
  • 500 Ohms/ft Of Resistance
  • 550 F Rated Silicone Jacket
  • Stainless Steel Plug Terminals
  • High RFI Suppression For Street And Strip Use
  • Universal And Import Coverage
  • High-strength Fiberglass Braid Construction
  • Pre And Post HEI Vehicles
  • 8mm High Gloss Silicone Jacket
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Best-Selling 1966 Cadillac Eldorado Spark Plugs

Upgrade your Eldorado with one of our 13 best-selling Spark Plugs, earning an average 4.82 stars rating across 75 reviews.

E3 – DiamondFIRE Spark Plug: More Power & Fuel Efficiency (Part No.E3.52)

DiamondFIRE Spark Plug: More Power & Fuel Efficiency

from

$8.49
The Premium DiamondFire Automotive Spark Plug is engineered to deliver exceptional performance and efficiency for your vehicle. Featuring E3’s patented Diamond Fire edge-to-edge ground electrode, it ensures a faster, more complete burn for smoother acceleration and idle. The innovative “diamond-shaped” side wire electrode enhances combustion by quickly igniting the air/fuel mixture, resulting in a larger and faster flame kernel. This translates to improved power output – up to 6% on average – and better fuel efficiency, saving you money while reducing engine carbon deposits. Constructed with durable nickel center and ground electrode tips, this spark plug is built to last. Its gasket seat type ensures a secure fit, and the pre-gapped design eliminates the need for adjustments, making installation hassle-free. With its advanced technology, this spark plug not only boosts engine performance but also contributes to a cleaner, more efficient combustion process.

Product Features:
  • E3’s Diamond Fire edge to edge ground electrode provides maximum performance with increased efficiency and a faster more complete burn.
  • Smoother Acceleration & Idle – The faster flame initiated by the spark plug results in a more complete burn of the ingested fuel charge. More pressure is created against the piston more fuel is put to work
  • Energy – Power output improved up to 6% on average in the typical operating ranges. Results will vary.
  • Efficiency – The “diamond shaped” side wire electrode projects the combustion spark in a way that more quickly ignites the air/fuel mixture, thereby creating a significantly faster and larger flame kernel. The result is that more fuel is put to work durin
  • E3’s patented Diamond Fire Technology provides a cleaner burning combustion, which translates into fuel savings and reduced engine carbon deposits
  • The Spark Plugs are pre-gapped at the factory and cannot be adjusted.
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NGK – V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance (Part No.3332)

V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance

from

$6.99
NGK V-Power spark plugs offer reliable performance and improved ignitability over standard nickel plugs. Engineered specifically for OE applications, the special V-cut nickel alloy center electrode and concave ground electrode of NGK’s V-Power spark plug increases ignitability providing quicker starts and smoother idle. NGK’s legendary high grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance. Trivalent metal plating ensures superior anti-corrosion and anti-seizing properties.

Product Features:
  • ACTUAL OE or EQUIVALENT DESIGN: OEM quality construction nickel alloy center electrode with V-groove provides consistent performance
  • RECOMMENDED USAGE: Best for vehicles with OE nickel alloy plugs, not recommended on vehicles with factory precious metal plugs
  • NGK’s OE CERAMIC TECHNOLOGY: High grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance
  • SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
  • COLD-ROLLED THREADS: Prevents cross-threading and damage to cylinder heads
  • TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal
  • Enhanced Ignitability: The V-cut nickel alloy center electrode and concave ground electrode design of NGK V-Power spark plugs provide quicker starts and smoother idle.
  • OE Application Specific: Engineered specifically for Original Equipment (OE) applications, ensuring compatibility and reliable performance.
  • V-Groove Tip Design: The unique V-Groove tip design of the XR5 model enhances ignitability and overall engine performance.
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Champion – Copper Plus Small Engine Spark Plug (J8C): Dependable Performance & Durability (Part No.841)

Copper Plus Small Engine Spark Plug (J8C): Dependable Performance & Durability

from

$3.79
The Copper Plus spark plug is engineered for dependable performance and durability, making it an ideal OE-type replacement for small engines. Featuring a copper core center electrode, it ensures precise heat control and increased conductivity, promoting longer life and consistent wear. Its nickel center and ground electrode tips, combined with a flat seat design, deliver enhanced reliability and superior performance. Built to ISO and SAE Standards, this spark plug resists fouling and offers exceptional corrosion resistance, ensuring it withstands tough conditions. Whether you’re maintaining a small engine or seeking a reliable replacement, this spark plug provides proven performance and value.

Product Features:
  • Copper Plus – Dependable Performance and Durability
  • OE type replacement plug
  • Resists fouling
  • Copper core center electrode allows for accurate control of heat range for longer life
  • Superior corrosion resistance
  • Built to ISO and SAE standards for proven performance
  • Increased Conductivity and Heat Control: The Champion Copper Plus Small Engine Spark Plug features a copper core electrode that enhances conductivity and heat management, ensuring good overall wear.
  • Enhanced Reliability: With a nickel center electrode tip material and flat seat type, this spark plug provides enhanced reliability and consistent performance for small engines.
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Autolite – Platinum Spark Plug: Enhanced Durability & Improved Performance (Part No.AP85)

Platinum Spark Plug: Enhanced Durability & Improved Performance

from

$4.99
Autolite Platinum spark plugs are crafted for superior performance and durability, making them ideal for older engine designs. Featuring a platinum center electrode firing tip, these spark plugs ensure quicker firing, smoother starts, and enhanced acceleration while boosting fuel efficiency. The platinum firing tip resists gap erosion, extending service life, while the high alumina ceramic insulator provides excellent thermal conductivity and insulation for added strength. A multi-rib insulator prevents flash-over, and the nickel-plated shell offers corrosion resistance for long-lasting durability. Designed with a flat gasket seat type, these spark plugs ensure a secure fit and optimal performance. With a mid-projection standard center electrode and nickel ground electrode tip, they deliver reliable ignition and consistent performance. Perfect for those seeking a performance-grade solution, Autolite Platinum spark plugs combine advanced materials and engineering to deliver value and dependability for your vehicle.

Product Features:
  • Engineered with a platinum firing tip that prevents gap erosion for longer service life.
  • Its high alumina ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • The multi-rib insulator prevents flash-over.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended life.
  • Gasket Seat Type: Ensures a secure fit and optimal performance.
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Champion – Copper Plus Small Engine Spark Plug (J8C): Dependable Performance & Durability (Part No.841-1)

Copper Plus Small Engine Spark Plug (J8C): Dependable Performance & Durability

from

$3.79
Copper Plus spark plug delivers reliable performance and durability, making it an ideal choice for small engines. Featuring a copper core center electrode, it ensures precise heat control and enhanced conductivity, promoting longer life and consistent wear. Built to ISO and SAE Standards, this OE-type replacement plug resists fouling and offers superior corrosion resistance, ensuring dependable operation in various conditions. The nickel-tipped center and ground electrodes further enhance its durability and performance, while the flat seat design ensures a secure fit. Whether you’re maintaining your equipment or replacing worn-out parts, this spark plug provides exceptional value with its proven performance and robust construction.

Product Features:
  • Resists fouling
  • Superior corrosion resistance
  • Dependable and proven performance
  • Increased conductivity and heat control for good overall wear
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Dorman – Help – Spark Plug Non-Foulers – 14mm Gasket Seat (Part No.42000)

Spark Plug Non-Foulers - 14mm Gasket Seat

from

$7.99
This spark plug non fouler is designed for easy installation on specified vehicles to protect spark plugs from fouling and damage. It is engineered for durability and reliable performance.

Product Features:
  • Direct replacement – this spark plug non fouler is designed for easy installation to protect spark plugs from fouling and damage on specified vehicles
  • Ideal solution – this non-fouler preserves spark plug life and is a reliable replacement for an original non-fouler that has failed due to corrosion
  • Durable construction – made from quality components to ensure reliable performance and a long service life
  • Trustworthy quality – backed by team of product experts in the United States and more than a century of automotive experience
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NGK – Iridium IX Spark Plug (XR5IX): Extreme Ignitability & Durability (Part No.7355)

Iridium IX Spark Plug (XR5IX): Extreme Ignitability & Durability

from

$16.99
NGK Iridium IX spark plugs are specifically designed for the performance enthusiast. Iridium IX provides outstanding acceleration, high fuel efficiency and durability. NGK Iridium IX plugs offer extreme ignitability and exceptional anti-fouling. Tapered cut ground electrode provides improved starting, idling and throttle response. The Iridium fine wire center electrode’s durability is six times harder than platinum. Iridium alloy’s extremely high melting point is perfect for today’s engines. For even greater performance consider upgrading to an NGK Ruthenium HX plug.

Product Features:
  • SINGLE IRIDIUM TIP: Fine wire 0.6 millimeter iridium tip center electrode ensures high durability and a consistently stable spark
  • IRIDIUM ALLOY CENTER ELECTRODE: Iridium’s density (6x that of platinum) and extremely high melting point is perfect for modern high efficiency engines
  • TAPERED CUT GROUND ELECTRODE: Reduced quenching design produces outstanding ignitability, improved acceleration, fuel efficiency and durability
  • SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
  • TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal
  • RECOMMENDED USAGE: Modified or high performance applications, or as an upgrade to OE nickel alloy spark plugs
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ACDelco – Copper Core Spark Plug: Reliable Performance & Durability (Part No.R43S)

Copper Core Spark Plug: Reliable Performance & Durability

from

$6.29
ACDelco Professional Conventional Spark Plugs are designed for reliability and efficient performance, and are a high quality replacement for many vehicles on the road today. Their high-quality copper cores and outstanding suppression characteristics deliver reliable performance. They are also available for Marine applications. These premium aftermarket replacement spark plugs are manufactured to meet your expectations for fit, form, and function.

Product Features:
  • Black Onyx coating helps reduce corrosion
  • Copper core provides great heat transfer and helps maximize plug durability
  • Ribbed suppressor seal extends resistance and helps prevent spark ‘flash over’ and misfires
  • Nickel-chrome alloy sheathing helps prevent corrosion on center electrode
  • Available for use in Marine applications
  • Some ACDelco Gold parts may have formerly appeared as ACDelco Professional
  • Premium aftermarket replacement part
  • Manufactured to meet specifications for fit, form, and function for General Motors vehicles as well as most makes and models
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Autolite – Copper Resistor Spark Plug: Quick Starts & Enhanced Durability (Part No.85)

Copper Resistor Spark Plug: Quick Starts & Enhanced Durability

from

$3.99
Autolite Copper spark plugs are expertly crafted to ensure reliable performance and long-lasting durability for your vehicle. Featuring a copper core center electrode, these plugs excel in thermal control and resist fouling, ensuring consistent operation. The high nickel alloy center and ground electrodes are designed for extended life, while the high alumina multi-rib ceramic insulator enhances thermal conductivity and provides superior insulation for added strength. With a nickel-plated shell, these spark plugs resist corrosion, making them ideal for long-term use. The mid-projection center electrode and flat seat type ensure a precise fit, while the resistor design minimizes electrical interference. Optimized for good fuel economy, these spark plugs help you maximize mileage and efficiency. Built with regular-grade materials and nickel-tipped electrodes, they deliver dependable performance and quick starts, meeting the demands of your vehicle or application.

Product Features:
  • The copper core center electrode aids in thermal control and improves resistance to fouling.
  • Its specially engineered high nickel alloy center and ground electrode provides extended life.
  • The high alumina multi-rib ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended periods.
  • Good Fuel Economy: Designed to optimize fuel efficiency, this spark plug helps you get the most out of every gallon.
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ACDelco – RAPIDFIRE Platinum Spark Plug: Reduces Misfires & Enhances Durability (Part No.7)

RAPIDFIRE Platinum Spark Plug: Reduces Misfires & Enhances Durability

from

$6.99
ACDelco Gold (Professional) RAPIDFIRE Spark Plugs are a high quality alternative to Original Equipment (OE) parts. These RAPIDFIRE Single Platinum Performance Spark Plugs are designed for everyday use and are a high quality replacement for many vehicles on the road today. These premium aftermarket spark plugs have high-quality suppressors that help prevent misfiring, an improved plug to boot seal, and a pure copper core for greater durability. These premium aftermarket replacement spark plugs are manufactured to meet your expectations for fit, form, and function. ACDelco Gold (Professional) parts are manufactured to meet your expectations for fit, form, and function, making them a smart choice for General Motors vehicles, as well as most makes and models, including special applications. These high-quality parts are backed by General Motors. Some ACDelco Gold parts may have formerly appeared as ACDelco Professional.

Product Features:
  • Solid state suppressor, with two-piece glass and brass seal, can help reduce radio frequency interference, regulates spark energy for long electrode life, and helps protect against high combustion pressures
  • Pure copper core provides great heat transfer and helps maximize plug durability
  • Platinum on center electrode enables superior spark characteristics and can reduce voltage requirements of the ignition system
  • Ribless insulator helps optimize plug to boot seal
  • Some ACDelco Gold parts may have formerly appeared as ACDelco Professional
  • Premium aftermarket replacement part
  • Manufactured to meet specifications for fit, form, and function for General Motors vehicles as well as most makes and models
  • High-Quality Suppressors: ACDelco Gold RAPIDFIRE Spark Plugs feature high-quality suppressors that help prevent misfiring, ensuring reliable performance for everyday use.
  • Improved Plug to Boot Seal: Designed with an improved plug to boot seal, these spark plugs provide a secure fit, enhancing overall engine performance and longevity.
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Accel – Shorty Copper Spark Plug (0437S): Enhanced Clearance & Heat Dissipation (Part No.8197)

Shorty Copper Spark Plug (0437S): Enhanced Clearance & Heat Dissipation

from

$51.99
ACCEL’s patented race proven spark plugs in a Shorty configuration. The overall length has been reduced 3/16 in to 3/8 in (depending on the specific spark plug) to gain critical air gap between the spark plug boot and the exhaust manifold or header tube. This helps eliminate burning the spark plug boot or dimpling the header tube. The shorter spark plug length also can make it easier to install an remove the spark plugs in certain applications where there is not a lot of room to fit a socket or move a wrench around. ACCEL Shorty Spark Plugs are made with a Copper core which is a better conductor than Platinum and Iridium. They deliver a stronger spark especially in high performance applications where high combustion pressures are present. Copper is much better at dissipating heat than other materials which lessens the chance of a misfire. ACCEL Shorty Spark Plugs are capable allowing you to open the gap exposing a larger flame kernel or close it if needed for high boost applications. All ACCEL Shorty Spark Plugs have machine rolled threads allowing for a more precise thread engagement and torque retention.

Product Features:
  • Eliminates Dimpling Headers For Added Clearance
  • Improves Spark Plug Access To Fit Socket Or Wrench
  • Shorter Overall Plug Length Vs. OE Style Plug
  • Copper Core Center Electrode
  • Projected Tip
  • Helps Eliminate Burned Spark Plug Boots
  • Shorty Header Spark Plug
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Champion – Copper Plus Spark Plug (RJ14YC): Dependable Performance & Durability (Part No.63)

Copper Plus Spark Plug (RJ14YC): Dependable Performance & Durability

from

$4.79
Copper Plus spark plug delivers dependable performance and durability, making it a reliable choice for maintaining your vehicle’s efficiency. Featuring a copper core center electrode, it ensures precise heat control and enhanced conductivity, promoting longer life and consistent wear. The nickel-tipped center and ground electrodes provide superior corrosion resistance, ensuring optimal performance even in demanding conditions. Designed to meet ISO and SAE Standards, this spark plug guarantees proven reliability and compatibility with standard replacement needs. Its flat seat type and built-in resistor further enhance its functionality, making it a practical solution for maintaining engine performance. Whether you’re seeking durability or consistent ignition, this spark plug offers excellent value for your vehicle’s maintenance.

Product Features:
  • Copper Plus – Dependable Performance.
  • Copper core center electrode allows for accurate control of heat range for longer life
  • Patented TinTac and ULTRASEAL coated shell for maximum corrosion resistance
  • Patented SAC-9 semiconductor resistor for maximum EMI & RFI suppression
  • Built to ISO and SAE standards for proven performance
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ACDelco – Double Platinum Spark Plug: Long-Lasting Performance & Durability (Part No.41-833)

Double Platinum Spark Plug: Long-Lasting Performance & Durability

from

$12.99
ACDelco Gold (Professional) Double Platinum Spark Plug are a high quality alternative to Original Equipment (OE) parts. With a copper core and double platinum pads on the center electrode, these plugs are designed to deliver long-lasting performance. These premium aftermarket replacement spark plugs are manufactured to meet your expectations for fit, form, and function. ACDelco Gold (Professional) parts are manufactured to meet your expectations for fit, form, and function, making them a smart choice for General Motors vehicles, as well as most makes and models, including special applications. These high-quality parts are backed by General Motors. Some ACDelco Gold parts may have formerly appeared as ACDelco Professional.

Product Features:
  • One-piece, fired-in suppressor seal blends three glass types for a gas-tight seal that helps reduce radio frequency and engine interference, regulate spark plug energy, and protect against compression pressures for long life
  • Double platinum point pad on center and ground electrode offer excellent durability and consistent voltage demands to help reduce wear on ignition system
  • Pure copper core results in cooler electrode temperature for maximized durability and fouling resistance
  • Some ACDelco Gold parts may have formerly appeared as ACDelco Professional
  • Premium aftermarket replacement part
  • Manufactured to meet specifications for fit, form, and function for General Motors vehicles as well as most makes and models
See More

Top-Rated Spark Plug Brands For Your 1966 Cadillac Eldorado

When it comes to finding the perfect Spark Plug for your 1966 Cadillac Eldorado, Advance Auto Parts has you covered with a wide selection of high-quality OEM and aftermarket options from 7 trusted brands. We carry the most popular Spark Plug brands including NGK, Champion, and Autolite, and more, all known for their exceptional customer ratings (average brand rating of 4.8 stars) and competitive prices, as low as $3.79. Purchasing a Spark Plug from us here at Advance Auto Parts is a smart move for both you and your 1966 Cadillac Eldorado, providing peace of mind with parts that meet or exceed OEM standards.

Popular NGK 1966 Cadillac Eldorado Spark Plugs

If you’re looking for a top-quality Spark Plug for your 1966 Cadillac Eldorado, Advance Auto Parts has exactly what you need with our selection of NGK Spark Plugs. We have 2 NGK Spark Plugs in stock for this fitment, all known for their durability and precision fit. With prices starting at just $6.99 and an average cost of $11.99, you’ll find the perfect Spark Plug for your needs and budget. NGK Spark Plugs for the 1966 Cadillac Eldorado come highly rated, with over 10 customer reviews and an impressive average rating of 4.8 stars. Choosing a NGK Spark Plug from Advance Auto Parts is a smart move to ensure quality and value for your vehicle.
Iridium IX Spark Plug (XR5IX): Extreme Ignitability & Durability
from $16.99
(1)
Iridium IX Spark Plug (XR5IX): Extreme Ignitability & Durability
“This is a high quality product”
V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance
from $6.99
(9)
V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance
“Yes they make the zap.zap when piston comes up to.compress fuel.and air”

Top-Quality Champion 1966 Cadillac Eldorado Spark Plugs

For those in search of a high-quality Spark Plug for their 1966 Cadillac Eldorado, Advance Auto Parts offers a great selection of Champion Spark Plugs. With 2 Champion Spark Plugs in stock, you can trust you’re getting top-tier parts designed for durability and a perfect fit. Prices for these Spark Plugs start at just $3.79, giving you a range of options to suit your budget. Backed by over 14 customer ratings and an average rating of 4.7 stars, Champion Spark Plugs provide both reliability and excellent performance. Choosing a Champion Spark Plug from Advance Auto Parts is a smart investment in your vehicle’s performance and longevity.
Copper Plus Small Engine Spark Plug (J8C): Dependable Performance & Durability
from $3.79
(1)
Copper Plus Small Engine Spark Plug (J8C): Dependable Performance & Durability
“Only Advance carried this hard to find plug. It works as it should.”
Copper Plus Small Engine Spark Plug (J8C): Dependable Performance & Durability
from $3.79
(13)
Copper Plus Small Engine Spark Plug (J8C): Dependable Performance & Durability
“Bought it for a Troy-Built Tomahawk chipper.”

FAQs for 1966 Cadillac Eldorado Spark Plugs

What are the best-selling Spark Plugs for 1966 Cadillac Eldorados?

Out of 15 Spark Plugs that fit 1966 Cadillac Eldorados, the following parts are the top sellers:

What’s the price range for 1966 Cadillac Eldorado Spark Plugs?

The prices of Spark Plugs for the 1966 Cadillac Eldorado range from $3.79 up to $99.99 for the most premium parts.

What is the average price of a Spark Plug for a 1966 Cadillac Eldorado?

The average price for Spark Plugs for the 1966 Cadillac Eldorado is $20.80. Keep in mind the variety of part types within our Spark Plug category, where you are likely to find a wide range of prices across a variety of parts and components.

Does Advance Auto Parts sell Spark Plugs for other Cadillac Eldorado model years?

Yes, we carry Spark Plugs for 48 model years of Cadillac Eldorados between 1953 and 2002. The following model years are the most popular for Spark Plug purchases: 2002, 2001, 2000, 1999, 1998, 1997, 1996, 1995, and 1994.

What are the cheapest Spark Plugs for my 1966 Cadillac Eldorado?

Does Advance Auto Parts sell Spark Plugs for any other 1966 Cadillac models?

Yes. We stock Spark Plugs for 3 other popular 1966 Cadillac models. Some of the most popular are 1966 DeVille Spark Plugs, 1966 Fleetwood Spark Plugs, 1966 Calais Spark Plugs, and 1966 Commercial Chassis Spark Plugs.

What are the top-rated Spark Plugs that fit the 1966 Cadillac Eldorado?

Based on 82 reviews by customers, our 1966 Cadillac Eldorado Spark Plugs have an average customer rating of 5 stars. These are the highest-rated categories of Spark Plugs for the 1966 Cadillac Eldorado and their top-rated products:

What types of Spark Plugs do you sell for my 1966 Cadillac Eldorado?

As of 11/2/25, these are some of the most in-demand types of Spark Plugs for a 1966 Cadillac Eldorado:

Can I get help with 1966 Cadillac Eldorado Spark Plug orders?

Contact our customer support team by chat or phone, through the help desk page, where you can find instant answers about Cadillac Spark Plugs and more.

What is your return policy for Cadillac Eldorado Spark Plugs?

Advance Auto Parts keeps returns simple. For new Cadillac Eldorado Spark Plugs and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.