1977 Cadillac Eldorado Spark Plugs

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Keep Your 1977 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 1977 Cadillac Eldorado looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Spark Plugs, Spark Plug Wire Set Cut To Fits, 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 Autolite, Champion, and MSD Ignition. For example, Autolite Spark Plugs start at just $3.99 with an average 4.6 star rating. Champion and MSD Ignition offer similar pricing and quality, backed by strong customer feedback. With over 100 reviews and a solid 4 star average, you can shop with confidence knowing other Cadillac Eldorado owners approve.

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 1977 Cadillac Eldorado in peak condition, inside and out.

Essential 1977 Cadillac Eldorado Spark Plugs

DENSO – Iridium Power Spark Plug: Maximum Spark Energy, 0.4mm Iridium Tip, ITF16 (Part No.5330)

Iridium Power Spark Plug: Maximum Spark Energy, 0.4mm Iridium Tip, ITF16

from

$12.99
The Iridium Power Spark Plug (ITF16) is engineered for unmatched performance and efficiency, featuring the world’s smallest 0.4mm Iridium Center Electrode for enhanced spark and maximum combustion. Its patented 360-degree laser welding ensures durability, while the U-groove and taper-cut ground electrode optimize flame propagation for superior ignition. Built to withstand extreme temperatures exceeding 4000 Deg F, this spark plug is burnished with nickel plating for exceptional corrosion resistance and high-temperature endurance. Designed for a wide range of applications, including classic and collector cars, it delivers superior performance with more horsepower, quicker starts, and fewer misfires under heavy loads. The advanced iridium technology enhances fuel efficiency, making it a cost-effective choice, while its low voltage requirement ensures reliable ignition with reduced energy consumption. Whether you’re seeking maximum power or improved fuel economy, this spark plug is built to perform under the most demanding conditions.

Product Features:
  • World’s smallest Iridium Center Electrode (0.4mm) for improved spark for maximum combustion
  • Patented 360-degree laser welding assembly process
  • U-groove and taper cut ground electrode to maximize flame propagation.
  • Withstands temperatures greater than 4000 degree Fahrenheit
  • Burnished nickel plating for high temperature endurance and superior corrosion resistance
  • Wide range of part numbers for thousands of applications, including classic and collector cars
  • Iridium Power
  • Superior Performance: Designed for maximum performance under extreme conditions, this spark plug delivers more horsepower, faster and easier starts, and fewer misfires under heavy loads.
  • Enhanced Fuel Efficiency: The advanced iridium technology of the DENSO Iridium Power spark plug contributes to better fuel efficiency, making it an economical choice for your vehicle.
  • Low Voltage Requirement: This spark plug requires 5,000 volts less to fire compared to conventional spark plugs, ensuring reliable ignition with lower energy consumption.
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ACDelco – Double Platinum Spark Plug (Part No.41-902)

Double Platinum Spark Plug

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
  • Pure copper core results in cooler electrode temperature for maximized durability and fouling resistance
  • 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
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Autolite – Double Platinum Spark Plug: Enhanced Durability & Performance (Part No.APP605)

Double Platinum Spark Plug: Enhanced Durability & Performance

from

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

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

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$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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ACDelco – Double Platinum Spark Plug (Part No.41-987)

Double Platinum Spark Plug

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
  • Pure copper core results in cooler electrode temperature for maximized durability and fouling resistance
  • 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
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NGK – Iridium IX Spark Plug (TR55IX): Outstanding Acceleration & Durability (Part No.7164)

Iridium IX Spark Plug (TR55IX): Outstanding Acceleration & Durability

from

$14.99
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 c

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 – Gas Engine Ignition Spark Plug (Part No.R45XLS)

Gas Engine Ignition Spark Plug

from

$5.99
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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ACDelco – Professional Double Platinum Spark Plug: Enhanced Durability & Performance (Part No.41-963)

Professional Double Platinum Spark Plug: Enhanced Durability & Performance

from

$4.49
ACDelco is a global leader in automotive replacement parts and related services and offers quality aftermarket products for most makes and models, including General Motors, Ford, Chrysler, Toyota and Honda, plus many original equipment service replacement parts. ACDelco products can be found in more than 100 countries located on six of the seven continents and are sourced globally to meet the needs of the local markets, including “maintenance” parts commonly replaced during the lifetime of a vehicle (e.g., batteries, oil filters, air filters, wiper blades, shocks and brakes), as well as “repair” parts (e.g., alternators, radiators, chassis and heating/cooling components). ACDelco offers more than 80,000 parts across 37 product lines. ACDelco has over 100 years of experience in the automotive industry and is a brand of GM Customer Care and Aftersales, a division of General Motors. ACDelco employs a two- or three-tiered distribution model, utilizing a network of appointed wholesale distributors to service independent installers, ACDelco independent service centers, retail and fleet customers.

Product Features:
  • The kind of firepower you expect from ACDelco. The spark plug is what started it all for us, and with over 100 years of innovation behind each spark plug, you know they’re going to be great.
  • Designed for enhanced durability and consistent performance, ensuring reliable ignition over an extended lifespan.
  • Engineered to meet the needs of a wide range of vehicle makes and models, including General Motors, Ford, Toyota, and Honda.
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Accel – Universal Fit Super Stock 8mm Suppression; Spark Plug Wire Set (Part No.4040R)

Universal Fit Super Stock 8mm Suppression; Spark Plug Wire Set

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$73.99
These ACCEL wire sets are a true performance upgrade replacement for OE types. Efficient delivery of spark energy for a good price. Silicone boots with black wire contain zinc-plated steel terminals. Noise suppression core. Set contains 8 plug wires with coil lead.

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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MSD Ignition – Wire Set; Super Conductor; 8-cyl. Multi-Angle Plug; Socket/HEI (Part No.31199)

Wire Set; Super Conductor; 8-cyl. Multi-Angle Plug; Socket/HEI

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$143.99
Set includes terminals for engines with early type (socket) and late type (HEI spark plug top) distributor caps. 90 degree boots and terminals factory installed on one end.

Product Features:
  • Extra Long 8.5mm Wires So You Can Cut To Your Designed Length
  • Incl. both socket-style and spark plug-style boots and terminals
  • Includes Mini-Stripper-Crimper For Factory Style Crimps
  • Size Includes: [2]48/50/56 in./[3] 32 in. Wires/Boots/Terminals
  • Durable outer sleeve is a proprietary compound for resistance to high heat or abrasion
  • Stainless steel terminals feature dual crimp tabs to grip wire conductor and outer jacket separately
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Dorman – Help – Spark Plug Non-Foulers – 14mm Tapered Seat (Part No.42006)

Spark Plug Non-Foulers - 14mm Tapered Seat

from

$7.59
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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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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Dorman – Help – Spark Plug Non-Foulers – 14mm Gasket Seat Long Reach (Part No.42004)

Spark Plug Non-Foulers - 14mm Gasket Seat Long Reach

from

$9.99
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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Most Popular Spark Plugs for 1977 Cadillac Eldorados

Enhance your 1977 Cadillac Eldorado with one of the 9 Spark Plugs we have in stock, starting at just $3.99.

Champion – Double Platinum Power Spark Plug (RN14PMP5): Enhanced Ignitability & Durability (Part No.7031)

Double Platinum Power Spark Plug (RN14PMP5): Enhanced Ignitability & Durability

from

$9.99
Champion Double Platinum Power spark plugs are engineered for superior performance and durability, making them an ideal choice for standard replacement needs. Featuring a platinum fine-wire center electrode and a platinum pad ground electrode, these spark plugs deliver exceptional wear resistance and maintain stable operating temperatures under all engine loads. The innovative Heat-Active alloy ensures the electrodes reach optimal temperature quickly, enhancing efficiency and reliability. With a V-trimmed ground electrode design, these spark plugs promote sharper spark focus for improved ignitability and smoother engine operation. Designed with a flat seat type and integrated resistor, they provide consistent performance while reducing electrical interference. Perfect for drivers seeking enhanced ignitability and long-lasting durability, these spark plugs are built to meet the demands of modern engines.

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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NGK – V-Power Nickel Spark Plug (GR45): Enhanced Ignitability & Performance (Part No.4268)

V-Power Nickel Spark Plug (GR45): 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 GR45 model enhances ignitability and overall engine performance.
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Autolite – Double Platinum Spark Plug: Enhanced Durability & Performance (Part No.APP646)

Double Platinum Spark Plug: Enhanced Durability & Performance

from

$6.99
Double Platinum Spark Plug offers enhanced durability and performance with its platinum-to-platinum design, effectively reducing gap erosion and misfires for a longer service life. Engineered for distributor-less ignition system (DIS) engines, it outperforms copper and standard platinum plugs. The yttrium-enhanced ground electrode ensures superior heat transfer, maintaining durability under high temperatures and pressure. Its high alumina ceramic insulator optimizes thermal conductivity and dielectric strength, while the multi-rib insulator prevents flash-over for reliable operation. Featuring a mid-projection center electrode and flat seat type, this performance-grade spark plug is built with platinum tips on both the center and ground electrodes for consistent ignition and efficiency. Designed to withstand demanding conditions, it delivers exceptional value for drivers seeking reliability and long-lasting performance.

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.
  • Designed with a mid-projection center electrode and flat seat type to ensure consistent ignition and optimized performance in demanding conditions.
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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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E3 – DiamondFire Spark Plug (E3.46): Enhanced Power & Fuel Efficiency (Part No.E3.46)

DiamondFire Spark Plug (E3.46): Enhanced Power & Fuel Efficiency

from

$8.49
The Spark Plugs are the product of years of fundamental research in the combustion field. The unique patented electrode configuration of these new The spark plugs increases the amount of combustion pressure created during each power stroke of an engine, which results in a marked increase in power output, fuel economy, and reduced emissions in all gasoline engines. E3.46 is a 14mm, 0.750 reach plug with a gasket seat. It fits a wide variety of applications from the 60s to early 90s, especially import. E3.46 is widely stocked in automotive retail stores. The automotive plugs have three legs securing the Diamond FIRE electrode to the shell. This allows for excellent heat transfer, and helps to create more turbulence in the cylinder. The patented Diamond FIRE side wire is proven to increase power, reduce fuel consumption and improve hydrocarbon emissions in long-term use.

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.
  • Wide Compatibility: The E3.46 spark plugs are 14mm with a 0.750 reach and a gasket seat, making them suitable for a wide range of applications from the 1960s to early 1990s, especially for import vehicles.
  • Widely Available: The E3.46 spark plugs are widely stocked in automotive retail stores, ensuring easy availability for consumers.
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Autolite – Platinum Spark Plug: Enhanced Durability & Improved Performance (Part No.AP646)

Platinum Spark Plug: Enhanced Durability & Improved Performance

from

$4.99
Autolite Platinum spark plugs are expertly crafted to deliver exceptional performance and durability for older engine applications. Featuring a platinum center electrode firing tip, these spark plugs resist gap erosion, ensuring a longer service life and consistent reliability. The high alumina ceramic insulator enhances thermal conductivity and insulation, providing superior strength under demanding conditions. A multi-rib insulator design prevents flash-over, while the nickel-plated shell offers outstanding corrosion resistance for extended durability. With a necked-down center electrode, these spark plugs fire quicker and cleaner, requiring less voltage for smoother starts, faster acceleration, and improved fuel efficiency. Designed with a mid-projection standard center electrode and a flat seat type, they are tailored for performance-grade applications. The combination of platinum and nickel materials ensures optimal conductivity and durability, making these spark plugs a smart choice for drivers seeking enhanced engine efficiency and long-lasting reliability.

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.
  • Necked-down center electrode fires quicker and cleaner with less voltage for easier starts, quicker acceleration, and improved fuel economy
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ACDelco – RAPIDFIRE Spark Plug (Part No.4)

RAPIDFIRE Spark Plug

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.

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: These spark plugs are equipped with high-quality suppressors that help prevent misfiring, ensuring smooth and efficient engine operation.
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ACDelco – Conventional Spark Plug (Part No.R45XLS6)

Conventional Spark Plug

from

$5.99
ACDelco GM Original Equipment Conventional Spark Plugs are designed, engineered, and tested to rigorous standards, and are backed by General Motors. 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 GM Original Equipment parts are the true OE parts installed during the production of 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:
  • 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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NGK – G-Power Platinum Spark Plug (GR45GP): Enhanced Durability & Efficiency (Part No.3142)

G-Power Platinum Spark Plug (GR45GP): Enhanced Durability & Efficiency

from

$5.99
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.

Product Features:
  • SINGLE PLATINUM TIP: Fine wire 0.6 millimeter platinum tip center electrode ensures improved durability and a consistently stable spark
  • PLATINUM ALLOY: G-Power platinum provides exceptional value with increased performance and longer service intervals than factory nickel plugs
  • TRAPEZOIDAL CUT GROUND ELECTRODE: Reduces quenching design produces improved ignitability and 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
  • RECOMMENDED USAGE: Lower cost alternative to double precious metal spark plugs or as an upgrade to OE nickel alloy spark plugs
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Best-Selling 1977 Cadillac Eldorado Spark Plug Wire Set Cut To Fits

Upgrade your Eldorado with one of our 2 best-selling Spark Plug Wire Set Cut To Fits, earning an average 4 stars rating across 4 reviews.

MSD Ignition – Wire Set; Super Conductor; 8-cyl. Multi-Angle Plug; Socket/HEI (Part No.31199)

Wire Set; Super Conductor; 8-cyl. Multi-Angle Plug; Socket/HEI

from

$143.99
Set includes terminals for engines with early type (socket) and late type (HEI spark plug top) distributor caps. 90 degree boots and terminals factory installed on one end.

Product Features:
  • Extra Long 8.5mm Wires So You Can Cut To Your Designed Length
  • Incl. both socket-style and spark plug-style boots and terminals
  • Includes Mini-Stripper-Crimper For Factory Style Crimps
  • Size Includes: [2]48/50/56 in./[3] 32 in. Wires/Boots/Terminals
  • Durable outer sleeve is a proprietary compound for resistance to high heat or abrasion
  • Stainless steel terminals feature dual crimp tabs to grip wire conductor and outer jacket separately
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Accel – Universal Fit Super Stock 8mm Suppression; Spark Plug Wire Set (Part No.4040R)

Universal Fit Super Stock 8mm Suppression; Spark Plug Wire Set

from

$73.99
These ACCEL wire sets are a true performance upgrade replacement for OE types. Efficient delivery of spark energy for a good price. Silicone boots with black wire contain zinc-plated steel terminals. Noise suppression core. Set contains 8 plug wires with coil lead.

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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Top-Quality Spark Plug Non-Foulers for 1977 Cadillac Eldorados

Choose a high-quality OEM or aftermarket Spark Plug Non-Fouler for Cadillac Eldorados and enjoy top-notch performance from $9.99.

Dorman – Help – Spark Plug Non-Foulers – 14mm Gasket Seat Long Reach (Part No.42004)

Spark Plug Non-Foulers - 14mm Gasket Seat Long Reach

from

$9.99
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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Top-Rated Spark Plug Brands For Your 1977 Cadillac Eldorado

When it comes to finding the perfect Spark Plug for your 1977 Cadillac Eldorado, Advance Auto Parts has you covered with a wide selection of high-quality OEM and aftermarket options from 8 trusted brands. We carry the most popular Spark Plug brands including Champion, Autolite, and MSD Ignition, and more, all known for their exceptional customer ratings (average brand rating of 4.7 stars) and competitive prices, as low as $3.99. Purchasing a Spark Plug from us here at Advance Auto Parts is a smart move for both you and your 1977 Cadillac Eldorado, providing peace of mind with parts that meet or exceed OEM standards.

Popular Champion 1977 Cadillac Eldorado Spark Plugs

If you’re looking for a top-quality Spark Plug for your 1977 Cadillac Eldorado, Advance Auto Parts has exactly what you need with our selection of Champion Spark Plugs. We have 1 Champion Spark Plugs in stock for this fitment, all known for their durability and precision fit. With prices starting at just $9.99, you’ll find the perfect Spark Plug for your needs and budget. Champion Spark Plugs for the 1977 Cadillac Eldorado come highly rated, with over 8 customer reviews and an impressive average rating of 4.7 stars. Choosing a Champion Spark Plug from Advance Auto Parts is a smart move to ensure quality and value for your vehicle.

Top-Quality Autolite 1977 Cadillac Eldorado Spark Plugs

For those in search of a high-quality Spark Plug for their 1977 Cadillac Eldorado, Advance Auto Parts offers a great selection of Autolite Spark Plugs. With 3 Autolite 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 $3.99, with an average price of $5.32, giving you a range of options to suit your budget. Backed by over 15 customer ratings and an average rating of 4.6 stars, Autolite Spark Plugs provide both reliability and excellent performance. Choosing a Autolite Spark Plug from Advance Auto Parts is a smart investment in your vehicle’s performance and longevity.
Copper Resistor Spark Plug: Quick Starts & Enhanced Durability
from $3.99
(5)
Copper Resistor Spark Plug: Quick Starts & Enhanced Durability
“Though copper plugs don’t last as long as platinum, they run smoother in older cars that lack the sophisticated ignition timing computers of the newer”
Double Platinum Spark Plug: Enhanced Durability & Performance
from $6.99
(2)
Double Platinum Spark Plug: Enhanced Durability & Performance
“Good plugs for my application.”

FAQs for 1977 Cadillac Eldorado Spark Plugs

What are the best-selling Spark Plugs for 1977 Cadillac Eldorados?

Out of 12 Spark Plugs that fit 1977 Cadillac Eldorados, the following parts are the top sellers:

What’s the price range for 1977 Cadillac Eldorado Spark Plugs?

The prices of Spark Plugs for the 1977 Cadillac Eldorado range from $3.99 up to $143.99 for the most premium parts.

What is the average price of a Spark Plug for a 1977 Cadillac Eldorado?

The average price for Spark Plugs for the 1977 Cadillac Eldorado is $24.12. 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 1977 Cadillac Eldorado?

Does Advance Auto Parts sell Spark Plugs for any other 1977 Cadillac models?

Yes. We stock Spark Plugs for 3 other popular 1977 Cadillac models. Some of the most popular are 1977 DeVille Spark Plugs, 1977 Seville Spark Plugs, 1977 Fleetwood Spark Plugs, and 1977 Commercial Chassis Spark Plugs.

What are the top-rated Spark Plugs that fit the 1977 Cadillac Eldorado?

Based on 100 reviews by customers, our 1977 Cadillac Eldorado Spark Plugs have an average customer rating of 4 stars. These are the highest-rated categories of Spark Plugs for the 1977 Cadillac Eldorado and their top-rated products:

What types of Spark Plugs do you sell for my 1977 Cadillac Eldorado?

As of 3/1/26, these are some of the most in-demand types of Spark Plugs for a 1977 Cadillac Eldorado:

Can I get help with 1977 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.