1966 Cadillac Eldorado Spark Plugs

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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 Plugs and Spark Plug Non-Foulers. 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 NGK, Champion, and Autolite. For example, NGK Spark Plugs start at just $6.99 with an average 4.8 star rating. Champion and Autolite offer similar pricing and quality, backed by strong customer feedback. With over 75 reviews and a solid 4.8 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 $11.11, with a range that starts at $4.29 and goes up to $55.19. With 13 options in stock from 7 trusted brands, finding the right fit is easy. Popular picks like ACDelco Conventional Spark Plug, R43S, E3 DiamondFIRE Spark Plug: More Power & Fuel Efficiency, E3.52, and NGK V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance, 3332 start at just $6.49 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

Dorman – Help – Dorman – Help Spark Plug Non-Foulers – 14mm Tapered Seat, 42008 (Part No.42008)

Dorman - Help Spark Plug Non-Foulers - 14mm Tapered Seat, 42008

from

$10.49
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.
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Dorman – Help – Dorman – Help Spark Plug Non-Foulers – 14mm Gasket Seat, 42000 (Part No.42000)

Dorman - Help Spark Plug Non-Foulers - 14mm Gasket Seat, 42000

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.
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Dorman – Help – Dorman – Help Spark Plug Non-Foulers – 14mm Tapered Seat, 42006 (Part No.42006)

Dorman - Help Spark Plug Non-Foulers - 14mm Tapered Seat, 42006

from

$8.49
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.
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E3 – E3 DiamondFIRE Automotive Spark Plug: More Power & Fuel Efficiency, E3.54 (Part No.E3.54)

E3 DiamondFIRE Automotive Spark Plug: More Power & Fuel Efficiency, E3.54

from

$8.49
“The Premium DiamondFire Automotive Spark Plug is engineered to deliver peak 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 flame kernel and improved power output – up to 6% on average. This advanced design not only boosts energy but also promotes fuel savings and reduces engine carbon deposits for a cleaner, more efficient operation. Constructed with durable nickel center and ground electrode tips, it offers long-lasting reliability. The tapered seat type ensures a secure fit, and the pre-gapped design eliminates the need for adjustments, making installation hassle-free. Upgrade to this spark plug for enhanced performance, better fuel economy, and a cleaner engine.”
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Motorcraft – Motorcraft Spark Plug: Reliable Ignition & Engine Efficiency, SP-423-A (Part No.SP-423-A)

Motorcraft Spark Plug: Reliable Ignition & Engine Efficiency, SP-423-A

from

$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.
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DENSO – DENSO Platinum TT Spark Plug – PT16TT, 4511 (Part No.4511)

DENSO Platinum TT Spark Plug - PT16TT, 4511

from

$6.99
The Platinum TT Spark Plug with its innovative Twin-Tip design ensures faster flame propagation, promoting more complete combustion for enhanced engine performance and efficiency. Crafted with a durable platinum center electrode tip, this spark plug offers exceptional longevity and consistent performance, making it a reliable choice for your vehicle. Its tapered seat type ensures a secure fit, reducing the risk of gas leakage and optimizing combustion chamber sealing. Designed for precision and durability, this spark plug not only improves ignition efficiency but also contributes to smoother engine operation and potentially better fuel economy. A perfect blend of advanced technology and robust materials, it delivers excellent value for drivers seeking long-lasting performance and reliability.
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ACDelco – ACDelco RAPIDFIRE Spark Plug, 2 (Part No.2)

ACDelco RAPIDFIRE Spark Plug, 2

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.
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Champion – Champion Copper Plus Small Engine Spark Plug J8C – Dependable Performance & Durability, 841-1 (Part No.841-1)

Champion Copper Plus Small Engine Spark Plug J8C - Dependable Performance & Durability, 841-1

from

$4.29
Champion Copper Plus spark plugs deliver dependable ignition performance with proven copper-core technology. The copper core electrode provides excellent conductivity and optimized heat control for consistent sparks while the coated shell protects against corrosion. Champion your engine with spark plugs engineered to improve efficiency and keep your vehicle running at its best.
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Autolite – Autolite Copper Resistor Spark Plug: Quick Starts & Enhanced Durability, 85 (Part No.85)

Autolite Copper Resistor Spark Plug: Quick Starts & Enhanced Durability, 85

from

$4.49
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.
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Autolite – Autolite Copper Resistor Spark Plug: Quick Starts & Reliable Performance, 605 (Part No.605)

Autolite Copper Resistor Spark Plug: Quick Starts & Reliable Performance, 605

from

$4.49
Autolite Copper spark plugs are designed to provide quick starts and reliable performance, making them an essential upgrade 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 high alumina multi-rib ceramic insulator enhances thermal conductivity and insulation strength. With a nickel-plated shell, these plugs resist corrosion, offering long-lasting durability. The tapered seat design ensures a perfect fit for easy and reliable installation. Built with a mid-projection standard center electrode and nickel tip materials, these regular-grade spark plugs deliver dependable performance. Equipped with a resistor, they are tailored to meet the demands of modern engines, providing the power and efficiency your vehicle needs.
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NGK – NGK G-Power Platinum Spark Plug: Enhanced Durability & Fuel Efficiency, 3207 (Part No.3207)

NGK G-Power Platinum Spark Plug: Enhanced Durability & Fuel Efficiency, 3207

from

$8.99
NGK G-Power Platinum spark plugs are the best single platinum spark plugs at an economical price. G-Power plugs feature a fine wire platinum center electrode and a trapezoidal cut ground electrode that offers increased durability, improved fuel efficiency, lower emissions, faster starts and quicker acceleration over conventional nickel spark plugs. An excellent upgrade for vehicles which used nickel alloy spark plugs originally. For better performance consider upgrading to a NGK Iridium IX plug. For even greater performance consider upgrading to a NGK RUTHENIUM HX plug.
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Motorcraft – Motorcraft Spark Plug: Reliable Ignition with Nickel Electrode Design, SP-447-X (Part No.SP-447-X)

Motorcraft Spark Plug: Reliable Ignition with Nickel Electrode Design, SP-447-X

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$5.29
This spark plug is engineered for reliable ignition performance, featuring a standard center electrode design and durable nickel construction for both the center and ground electrode tips. The nickel material ensures excellent conductivity and resistance to wear, making it a dependable choice for maintaining consistent engine performance. Its tapered seat type provides a secure fit, enhancing the overall efficiency of the ignition system. Designed to deliver long-lasting durability and optimal functionality, this spark plug is a cost-effective solution for keeping your vehicle running smoothly. Whether you’re replacing a worn-out plug or performing routine maintenance, this high-quality component ensures dependable starts and efficient combustion.
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Autolite – Autolite Platinum Spark Plug (AP605): Enhanced Durability & Performance (Part No.AP605)

Autolite Platinum Spark Plug (AP605): Enhanced Durability & Performance

from

$5.49
The Platinum Spark Plug (AP605) is expertly crafted to deliver enhanced durability and performance for older engine applications. 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 provides superior thermal conductivity and insulation, boosting strength and reliability under demanding conditions. The multi-rib insulator design effectively prevents flash-over, while the nickel-plated shell offers exceptional corrosion resistance, extending the plug’s lifespan. With a mid-projection standard center electrode and a tapered seat type, this performance-grade spark plug is built to optimize engine functionality. The combination of platinum and nickel materials in the electrode tips ensures consistent performance and durability, making it a dependable choice for maintaining acceleration and overall engine efficiency.
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DENSO – DENSO Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, ITF16TT, 4715 (Part No.4715)

DENSO Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, ITF16TT, 4715

from

$15.49
The Iridium TT Spark Plug combines the durability of an OE-style plug with the power and torque of high-performance engineering. Featuring the world’s smallest 0.4mm Iridium Center Electrode, it maximizes firing potential while the 0.7mm Needle Tip Ground Electrode promotes higher spark energy and minimizes heat quenching. Built with DENSO’s patented Iridium-Rhodium alloy formula, it offers unmatched durability and withstands extreme temperatures exceeding 4000 Deg F. The advanced 360-degree laser welding process ensures a robust bond and structural integrity, while the Twin-Tip Technology, derived from OE Super Ignition Plug design, blends a fine wire Iridium Center Electrode with a Needle Tip Platinum Ground Electrode for ultimate endurance. This spark plug delivers over 100,000 miles of reliable performance, enhanced fuel economy, and reduced emissions, making it an eco-friendly and cost-effective choice. With premium materials and a tapered seat type, the Iridium TT Spark Plug is engineered for optimal performance and long-lasting reliability.
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E3 – E3 DiamondFIRE Automotive Spark Plug: More Power & Fuel Efficiency, E3.42 (Part No.E3.42)

E3 DiamondFIRE Automotive Spark Plug: More Power & Fuel Efficiency, E3.42

from

$8.49
DiamondFire Automotive Spark Plug delivers exceptional performance and efficiency with its innovative Diamond Fire edge-to-edge ground electrode design. Engineered for smoother acceleration and idle, it ensures a faster, more complete burn of the fuel charge, maximizing pressure against the piston and putting more fuel to work. With power output improved by up to 6% on average, this spark plug enhances energy efficiency while reducing engine carbon deposits thanks to its patented Diamond Fire Technology. The unique diamond-shaped side wire electrode ignites the air/fuel mixture quickly, creating a larger flame kernel for optimal combustion. Crafted with durable nickel center and ground electrode tips, it offers long-lasting reliability. Pre-gapped at the factory for hassle-free installation, this tapered seat spark plug is a smart choice for drivers seeking improved fuel savings, cleaner engine performance, and enhanced power output.
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ACDelco – ACDelco Conventional Spark Plug, R45S (Part No.R45S)

ACDelco Conventional Spark Plug, R45S

from

$6.49
ACDelco Gold (Professional) Conventional Spark Plugs are a high quality alternative to Original Equipment (OE) parts. These conventional spark plugs are designed for reliability and efficient performance. 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. 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.
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Motorcraft – Motorcraft Standard Spark Plug: Reliable Performance & Durability, SP-447 (Part No.SP-447)

Motorcraft Standard Spark Plug: Reliable Performance & Durability, SP-447

from

$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.
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Motorcraft – Motorcraft Double Platinum Spark Plug: Enhances Durability & Reduces Misfires, SP-486 (Part No.SP-486)

Motorcraft Double Platinum Spark Plug: Enhances Durability & Reduces Misfires, SP-486

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.
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Motorcraft – Motorcraft Double Platinum Spark Plug: Enhanced Durability & Reliability, SP-439-A (Part No.SP-439-A)

Motorcraft Double Platinum Spark Plug: Enhanced Durability & Reliability, SP-439-A

from

$7.79
Double Platinum Spark Plug by Motorcraft is the ultimate choice for maintaining peak performance and reliability in your Ford, Lincoln, or Mercury vehicle. Engineered to meet strict Ford standards, these spark plugs feature platinum center and ground electrode tips for exceptional durability and resistance to oxidation and arc erosion. Designed to eliminate misfires, reduce fuel consumption, and optimize emissions, they ensure smooth engine operation while protecting against false check engine lights. The multi-rib insulator adds an extra layer of protection against misfires, while the exact fit guarantees seamless installation. With service intervals of up to 100,000 miles, these spark plugs deliver long-lasting performance and value. Backed by Motorcraft’s Service Parts Warranty, they are crafted with high-quality materials to provide reliable performance across a wide range of domestic and import applications. Choose Motorcraft spark plugs for the same trusted quality that was in your vehicle when it rolled off the assembly line.
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ACDelco – ACDelco Double Platinum Spark Plug, 41-987 (Part No.41-987)

ACDelco Double Platinum Spark Plug, 41-987

from

$11.49
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.
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Autolite – Autolite Platinum Spark Plug: Enhanced Durability & Improved Performance, AP66 (Part No.AP66)

Autolite Platinum Spark Plug: Enhanced Durability & Improved Performance, AP66

from

$4.99
Autolite Platinum spark plugs are crafted for superior 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, better acceleration, and improved fuel efficiency. The platinum firing tip prevents gap erosion, extending the service life, while the high alumina ceramic insulator enhances 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 flat seat type, these performance-grade spark plugs deliver consistent results. The combination of platinum and nickel materials in the electrode tips further boosts reliability, making them a dependable choice for maintaining engine efficiency and longevity.
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NGK – NGK V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance, 3332 (Part No.3332)

NGK V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance, 3332

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.
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Motorcraft – Motorcraft Standard Spark Plug (AGSF52C): Reliable Performance & Durability, SP-442 (Part No.SP-442)

Motorcraft Standard Spark Plug (AGSF52C): Reliable Performance & Durability, SP-442

from

$3.29
Standard Spark Plug (AGSF52C) delivers reliable performance and durability, making it an ideal choice for maintaining your vehicle’s efficiency. Engineered to meet strict Ford standards, these Motorcraft spark plugs are designed to match specific engines, ensuring enhanced durability, reduced fuel consumption, and optimized emissions. With a tapered seat type and multi-rib insulator, they resist oxidation, arc erosion, and misfires, providing long-lasting reliability. Backed by Motorcraft’s Service Parts Warranty, these spark plugs are an exact fit for Ford, Lincoln, and Mercury vehicles, while also being suitable for a wide range of domestic and import cars and trucks. Crafted with high-quality materials, they offer service intervals of up to 100,000 miles, helping prevent false check engine lights and maintaining original equipment performance. Whether you’re replacing worn-out plugs or maintaining your vehicle’s factory standards, these spark plugs deliver confidence and reliability for almost any application.
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DENSO – DENSO Double Platinum Spark Plug: OE Performance, lasts 60K+ Miles, PT16EPR13, 5092 (Part No.5092)

DENSO Double Platinum Spark Plug: OE Performance, lasts 60K+ Miles, PT16EPR13, 5092

from

$11.99
The Double Platinum Spark Plug is engineered to deliver exceptional performance and durability, meeting the strictest OE standards for emissions and efficiency. Featuring OE-grade platinum on both the center and ground electrodes, it ensures superior thermal conductivity and sustained spark performance for over 60,000 miles. Its premium shell construction with machine-rolled threads enhances durability and provides a secure fit, while the tapered seat type improves combustion efficiency. Designed to reduce secondary required voltage, this spark plug increases ignition efficiency, leading to smoother engine operation and fewer shop comebacks. With its double platinum design and adherence to original equipment performance standards, this spark plug is a reliable choice for maintaining optimal engine efficiency and long-lasting performance.
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NGK – NGK Iridium IX Spark Plug (XR5IX): Extreme Ignitability & Durability, 7355 (Part No.7355)

NGK Iridium IX Spark Plug (XR5IX): Extreme Ignitability & Durability, 7355

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.
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ACDelco – ACDelco RAPIDFIRE Spark Plug, 14 (Part No.14)

ACDelco RAPIDFIRE Spark Plug, 14

from

$7.99
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.
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Accel – Accel Double Platinum Shorty Spark Plug – 14mm Thread, .708 in Reach, Tapered Seat – Single, P526S (Part No.P526S)

Accel Double Platinum Shorty Spark Plug - 14mm Thread, .708 in Reach, Tapered Seat - Single, P526S

from

$31.79
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 gapable 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.
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DENSO – DENSO Double Platinum Spark Plug: OE Performance, lasts 60K+ Miles, PT16EPR-L13, 5070 (Part No.5070)

DENSO Double Platinum Spark Plug: OE Performance, lasts 60K+ Miles, PT16EPR-L13, 5070

from

$12.49
Manufactured to the strictest OE performance, durability and emissions standards.
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Most Popular Spark Plugs for 1966 Cadillac Eldorados

Enhance your 1966 Cadillac Eldorado with one of the 12 Spark Plugs we have in stock, starting at just $4.29.

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

E3 DiamondFIRE Spark Plug: More Power & Fuel Efficiency, E3.52

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.”
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NGK – NGK V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance, 3332 (Part No.3332)

NGK V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance, 3332

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.
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Champion – Champion Copper Plus Small Engine Spark Plug J8C – Dependable Performance & Durability, 841 (Part No.841)

Champion Copper Plus Small Engine Spark Plug J8C - Dependable Performance & Durability, 841

from

$4.49
Champion Copper Plus spark plugs deliver dependable ignition performance with proven copper-core technology. The copper core electrode provides excellent conductivity and optimized heat control for consistent sparks while the coated shell protects against corrosion. Champion your engine with spark plugs engineered to improve efficiency and keep your vehicle running at its best.
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Autolite – Autolite Platinum Spark Plug: Enhanced Durability & Improved Performance, AP85 (Part No.AP85)

Autolite Platinum Spark Plug: Enhanced Durability & Improved Performance, AP85

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.
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Champion – Champion Copper Plus Small Engine Spark Plug J8C – Dependable Performance & Durability, 841-1 (Part No.841-1)

Champion Copper Plus Small Engine Spark Plug J8C - Dependable Performance & Durability, 841-1

from

$4.29
Champion Copper Plus spark plugs deliver dependable ignition performance with proven copper-core technology. The copper core electrode provides excellent conductivity and optimized heat control for consistent sparks while the coated shell protects against corrosion. Champion your engine with spark plugs engineered to improve efficiency and keep your vehicle running at its best.
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NGK – NGK Iridium IX Spark Plug (XR5IX): Extreme Ignitability & Durability, 7355 (Part No.7355)

NGK Iridium IX Spark Plug (XR5IX): Extreme Ignitability & Durability, 7355

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.
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ACDelco – ACDelco Conventional Spark Plug, R43S (Part No.R43S)

ACDelco Conventional Spark Plug, R43S

from

$6.49
ACDelco Gold (Professional) Conventional Spark Plugs are a high quality alternative to Original Equipment (OE) parts. These 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. 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.
See More

Autolite – Autolite Copper Resistor Spark Plug: Quick Starts & Enhanced Durability, 85 (Part No.85)

Autolite Copper Resistor Spark Plug: Quick Starts & Enhanced Durability, 85

from

$4.49
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.
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ACDelco – ACDelco RAPIDFIRE Spark Plug, 7 (Part No.7)

ACDelco RAPIDFIRE Spark Plug, 7

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.
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Accel – Accel HP Copper Spark Plug – Shorty – 14mm Thread – .375 in Reach – Gasket Seat – 8 Pack of 0437S, 8197 (Part No.8197)

Accel HP Copper Spark Plug - Shorty - 14mm Thread - .375 in Reach - Gasket Seat - 8 Pack of 0437S, 8197

from

$55.19
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 gapable 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.
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Champion – Champion Copper Plus Spark Plug RJ14YC – Dependable Performance & Durability, 63 (Part No.63)

Champion Copper Plus Spark Plug RJ14YC - Dependable Performance & Durability, 63

from

$4.99
Champion Copper Plus spark plugs deliver dependable ignition performance with proven copper-core technology. The copper core electrode provides excellent conductivity and optimized heat control for consistent sparks while the coated shell protects against corrosion. Champion your engine with spark plugs engineered to improve efficiency and keep your vehicle running at its best.
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ACDelco – ACDelco Double Platinum Spark Plug, 41-833 (Part No.41-833)

ACDelco Double Platinum Spark Plug, 41-833

from

$11.99
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.
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Best-Selling 1966 Cadillac Eldorado Spark Plug Non-Fouler

Upgrade your Eldorado with our best-selling Spark Plug Non-Fouler with a 5 Starts rating across 1 review.

Dorman – Help – Dorman – Help Spark Plug Non-Foulers – 14mm Gasket Seat, 42000 (Part No.42000)

Dorman - Help Spark Plug Non-Foulers - 14mm Gasket Seat, 42000

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$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.
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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 $4.29. 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.
NGK Iridium IX Spark Plug (XR5IX): Extreme Ignitability & Durability, 7355
from $16.99
(1)
NGK Iridium IX Spark Plug (XR5IX): Extreme Ignitability & Durability, 7355
“This is a high quality product”
NGK V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance, 3332
from $6.99
(9)
NGK V-Power Nickel Spark Plug (XR5): Enhanced Ignitability & Performance, 3332
“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 $4.29, with an average price of $4.39, giving you a range of options to suit your budget. Backed by over 14 customer ratings and an average rating of 4.8 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.
Champion Copper Plus Small Engine Spark Plug J8C - Dependable Performance & Durability, 841
from $4.49
(13)
Champion Copper Plus Small Engine Spark Plug J8C – Dependable Performance & Durability, 841
“Ready for me within one hour. No problem!”
Champion Copper Plus Small Engine Spark Plug J8C - Dependable Performance & Durability, 841-1
from $4.29
(1)
Champion Copper Plus Small Engine Spark Plug J8C – Dependable Performance & Durability, 841-1
“Only Advance carried this hard to find plug. It works as it should.”

FAQs for 1966 Cadillac Eldorado Spark Plugs

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

Out of 13 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 $4.29 up to $55.19 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 $11.11. 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.

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 75 reviews by customers, our 1966 Cadillac Eldorado Spark Plugs have an average customer rating of 4.8 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 8/2/26, 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.