1966 GMC L3500 Spark Plugs

Dependable performance. This Champion® spark plug features a copper core electrode that provides increased conductivity and heat control for good overall wear.

Product Features:

• Copper Plus – Dependable Performance and Durability
• Copper core center electrode allows for accurate control of heat range for longer life
• Superior corrosion resistance
• Built to ISO and SAE standards for proven performance
• Built to ISO and SAE standards for proven performance

With over 100 years of engineering expertise and more than 11 billion plugs sold, Autolite continues to set the standard. Designed and engineered in the USA, these spark plugs feature a copper cored center electrode for higher thermal conductivity and a specially engineered high nickel alloy center and ground electrode for extended life. The high alumina ceramic ensures high dielectric strength, while the leak-proof, heat-fused internal seal guarantees durability. Additionally, the multi-rib insulator prevents flash-over, making these spark plugs a reliable choice for any vehicle.

Product Features:

• Copper cored center electrode for higher thermal conductivity
• Specially engineered high nickel alloy center and ground electrode for extended life
• High alumina ceramic for high dielectric strength
• Leak proof, heat fused internal seal for durability
• Multi-rib insulator prevents flash-over
• Quick Starts and Smooth Acceleration: Designed to deliver quick starts and smooth acceleration, ensuring a reliable performance for your vehicle.
• Enhanced Fuel Economy: Engineered to provide good fuel economy, helping you save on fuel costs.

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. E3.52 is a 14mm, 0.375 reach plug with a gasket seat. It fits a wide variety of GM applications from the 50s to early 80s, and is generally the correct plug for older small block Chevrolet engines. 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 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.

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

With over 100 years of engineering expertise and more than 11 billion plugs sold, Autolite Platinum spark plugs are designed and engineered in the USA to deliver exceptional performance. Featuring a high nickel alloy side electrode that maintains a precise gap and a full platinum tip that ensures virtually no gap erosion, these spark plugs offer long-lasting durability. The necked-down center electrode fires quicker and cleaner with less voltage, resulting in easier starts, quicker acceleration, and improved fuel economy compared to standard plugs.

Product Features:

• High nickel alloy side electrode maintains precise gap
• Full platinum tip assures virtually no gap erosion for long life
• Necked-down center electrode fires quicker, cleaner with less voltage for easier starts, quicker acceleration and improved fuel economy (as compared to standard plugs)
• Improved Fuel Economy: Designed to enhance fuel efficiency compared to standard spark plugs.
• Engineered in the USA: Backed by over 100 years of engineering expertise and a legacy of more than 11 billion plugs sold.

With over 100 years of engineering expertise and more than 11 billion plugs sold, Autolite Platinum spark plugs are designed and engineered in the USA to deliver exceptional performance. Featuring a high nickel alloy side electrode that maintains a precise gap and a full platinum tip that ensures virtually no gap erosion, these spark plugs offer long-lasting durability. The necked-down center electrode fires quicker and cleaner with less voltage, resulting in easier starts, quicker acceleration, and improved fuel economy compared to standard plugs.

Product Features:

• High nickel alloy side electrode maintains precise gap
• Full platinum tip assures virtually no gap erosion for long life
• Necked-down center electrode fires quicker, cleaner with less voltage for easier starts, quicker acceleration and improved fuel economy (as compared to standard plugs)
• Improved Fuel Economy: Designed to enhance fuel efficiency compared to standard plugs.
• Gasket Seat Type: Ensures a secure fit and optimal performance.

Dependable performance. This Champion® spark plug features a copper core electrode that provides increased conductivity and heat control for good overall wear.

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

Dependable performance. This Champion® spark plug features a copper core electrode that provides increased conductivity and heat control for good overall wear.

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

Champion® Platinum Power spark plugs deliver powerful performance with their premium design. Featuring a platinum center electrode for long life and a fine-wire center electrode for greater ignitability, these spark plugs ensure optimal engine performance. The V-trimmed ground electrode promotes sharper spark focus, while the exclusive Heat-Active alloy allows the electrodes to reach optimal temperature. Additionally, the platinum-tipped center wire resists wear and helps maintain the proper gap specification throughout the life of the plug. With a flat seat type and integrated resistor, this spark plug is an ideal OE replacement.

Product Features:

• Platinum Power- Premium Spark Plug. Powerful Performance.
• Platinum center electrode for long life
• Fine-wire center electrode for greater ignitability
• V-trimmed ground electrode promotes sharper spark focus
• Heat-Active alloy allows electrodes to reach optimal temperature
• Platinum tipped center wire resists wear and helps to maintain proper gap spec over life of the plug
• Integrated Resistor and Flat Seat Type: Equipped with an integrated resistor and flat seat type, making it an ideal OE replacement for various engines.

Dependable Performance, OE Replacement, N5C. This Champion® spark plug features a copper core electrode that provides increased conductivity and heat control for good overall wear. Built to ISO and SAE standards, it offers dependable performance and durability with its Copper Plus technology. The OE type replacement plug resists fouling and boasts superior corrosion resistance. The nickel copper alloy center electrode allows for accurate control of heat range, ensuring a longer life and reliable performance. The flat seat type design further enhances its dependability.

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
• Enhanced Heat Control: The copper core electrode increases conductivity and heat control, ensuring good overall wear and a longer lifespan for the spark plug.
• Flat Seat Type Design: The flat seat type design of the Champion Copper Plus Small Engine Spark Plug further enhances its dependability and performance in various engine conditions.

Dependable performance. This Champion spark plug features a copper core electrode that provides increased conductivity and heat control for good overall wear.

Product Features:

• Resists fouling
• Superior corrosion resistance
• Dependable and proven performance
• Increased conductivity and heat control for good overall wear

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

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

With over 100 years of engineering expertise and more than 11 billion plugs sold, Autolite continues to innovate with its Copper Spark Plug. Designed and engineered in the USA, this spark plug features a copper-glass seal that bonds the insulator, terminal post, and center electrode together, ensuring full voltage at the spark gap and a 100% leak-proof, gas-tight seal. The multi-rib insulator reduces the risk of flash-over, while the one-piece terminal post adds strength and durability. Additionally, the built-in resistor minimizes radio frequency interference (RFI) and electrode erosion, making it a reliable choice for consistent performance.

Product Features:

• Copper-glass seal bonds insulator, terminal post center electrode together; assures full required voltage at spark gap; gas-tight seal (100% leak proof)
• Multi-rib insulator reduces danger of “flash-over”
• One-piece terminal post adds strength
• Resistor reduces radio frequency interference (RFI) and electrode erosion
• Quick Starts and Smooth Acceleration: The Autolite Copper Spark Plug is engineered to deliver quick starts and smooth acceleration, enhancing your vehicle’s performance.
• Good Fuel Economy: Designed to optimize fuel efficiency, this spark plug helps you get the most out of every gallon.

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 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.

Dependable Performance, OE Replacement, RJ12YC. This Champion® spark plug features a copper core electrode that provides increased conductivity and heat control for good overall wear. The Copper Plus design ensures dependable performance and durability, while the copper core center electrode allows for accurate control of heat range, extending the spark plug’s life. Built to ISO and SAE standards, it offers superior corrosion resistance and proven performance. The nickel center electrode tip and flat seat type further enhance its reliability, making it a top choice for maintaining your engine’s efficiency.

Product Features:

• Copper Plus – Dependable Performance and Durability
• Copper core center electrode allows for accurate control of heat range for longer life
• Superior corrosion resistance
• Built to ISO and SAE standards for proven performance
• Built to ISO and SAE standards for proven performance
• Dependable Performance: The Champion Copper Plus Spark Plug ensures reliable and consistent engine performance, making it an ideal OE replacement.
• Durable Design: The Copper Plus design guarantees durability and long-lasting performance, extending the life of the spark plug.

This Champion® spark plug features a copper core electrode that provides increased conductivity and heat control for good overall wear. Built to ISO and SAE standards for proven performance, it offers superior corrosion resistance and resists fouling. The copper core center electrode allows for accurate control of heat range for longer life, while the nickel center electrode tip material ensures durability. This OE type replacement plug is designed for dependable performance and durability, making it an excellent choice for maintaining your engine’s efficiency.

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 control, ensuring good overall wear.
• Durable Nickel Center Electrode Tip: The nickel center electrode tip material ensures durability, providing a longer lifespan for your engine’s spark plug.

Autolite has over 100 years of engineering experience and has sold over 11 billion plugs. Designed and engineered in the USA, Autolite Double Platinum spark plugs feature platinum-to-platinum firing which virtually eliminates gap erosion, reduces misfires and increases durability of the plug. Consider upgrading to Autolite Iridium XP spark plugs for increased performance.

Product Features:

• Works to optimize engine performance for a longer life and improved fuel economy
• OE design
• Full-platinum tips; platinum on both the center and side electrodes to promote reduced gap wear
• Platinum ball welding process provides a consistent point of contact for enhanced adhesion

Dependable Performance, OE Replacement, N12YC. This Champion® spark plug features a copper core electrode that provides increased conductivity and heat control for good overall wear. The Copper Plus design ensures dependable performance and durability, while the copper core center electrode allows for accurate control of heat range, extending the spark plug’s life. Built to ISO and SAE standards, it offers superior corrosion resistance and proven performance. The nickel center electrode tip and flat seat type further enhance its reliability, making it an excellent choice for maintaining your engine’s efficiency.

Product Features:

• Copper Plus – Dependable Performance and Durability
• Copper core center electrode allows for accurate control of heat range for longer life
• Superior corrosion resistance
• Built to ISO and SAE standards for proven performance
• Built to ISO and SAE standards for proven performance
• Nickel Center Electrode Tip: Equipped with a nickel center electrode tip, it provides accurate control of the heat range, further enhancing the spark plug’s reliability.
• Flat Seat Type: The flat seat type design ensures a secure fit, contributing to the overall efficiency and performance of your engine.

Autolite has over 100 years of engineering experience and has sold over 11 billion plugs. Guaranteed to deliver quick starts, good fuel economy and smooth acceleration, Autolite Copper Core spark plugs are designed to meet or exceed OES design requirements. Consider upgrading to Autolite Platinum, Double Platinum or Iridium XP plugs for improved engine performance. Copper core plugs are the industry standard.

Product Features:

• Copper-glass seal bonds insulator, terminal post center electrode together; assures full required voltage at spark gap; gas-tight seal (100% leak proof)
• Multi-rib insulator reduces danger of “flash-over”
• One-piece terminal post adds strength
• Resistor reduces radio frequency interference (RFI) and electrode erosion
• Quick Starts: Autolite Copper Core spark plugs are engineered to ensure your engine starts quickly and reliably every time.
• Good Fuel Economy: Designed to optimize fuel efficiency, these spark plugs help you get the most out of every gallon of gas.
• Smooth Acceleration: Experience smoother and more consistent acceleration with Autolite Copper Core spark plugs.
• OES Design Compliance: These spark plugs meet or exceed Original Equipment Service (OES) design requirements, ensuring high-quality performance.
• Industry Standard: Autolite Copper Core spark plugs are recognized as the industry standard, backed by over 100 years of engineering expertise and over 11 billion plugs sold.

Dependable performance. This Champion® spark plug features a copper core electrode that provides increased conductivity and heat control for good overall wear.

Product Features:

• Copper Plus – Dependable Performance and Durability
• Copper core center electrode allows for accurate control of heat range for longer life
• Superior corrosion resistance
• Built to ISO and SAE standards for proven performance
• Built to ISO and SAE standards for proven performance