1978 Chevrolet K20 Engine Additives

Keep Your 1978 Chevrolet K20 in Top Shape with Quality Engine Additives

Whether you’re repairing or upgrading your Engine Additive, using high-quality parts is key to keeping your 1978 Chevrolet K20 looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Posi Units and Components. 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.

Competitive Prices and Extensive Inventory

The average price for a 1978 Chevrolet K20 Engine Additive at Advance Auto Parts is around $301.66, with a range that starts at $259.99 and goes up to $376.99. With 3 options in stock from 2 trusted brands, finding the right fit is easy. Popular picks like Lock Right Locker, Differential Spool, and Differential Spool start at just $259.99 and offer a great balance of form and function.

Explore Related Parts

While you’re upgrading or replacing your Engine Additive, don’t forget to check out other key components like Coolant/Antifreeze and Fluids. At Advance Auto Parts, we’re here to help you keep your 1978 Chevrolet K20 in peak condition, inside and out.

Essential 1978 Chevrolet K20 Engine Additives

Powertrax – Lock Right Locker (Part No.1910-LR)

Lock Right Locker

from

$376.99
The Powertrax Lock-Right ultra-strength alloy locker’s straight-line performance is equal to a solid spool, but automatically unlocks in turns. Best suited for extreme off-road to severe on-road use, Powertrax Lock Right lockers replace the spider gears in your open differential carrier using basic tools and without affecting your ring and pinion settings. The whole job can be done in your driveway in a couple of hours, pin included! Powertrax Grip-Lok, Lock-Right Lockers and No-Slip Traction Systems automatically provide 100% traction on-demand, under the toughest circumstances. The Powertrax Grip-Pro and Grip-LS performance limited slips offer smooth dependable torque transfer and traction for the best of both worlds!The Powertrax® Lock-Right Locker provides outstanding traction for off-road machines and race vehicles. Powertrax No-Slip Traction Systems deliver excellent performance to street-driven cars and trucks.
  • Powertrax® lockers range from the original, Lock-Right for serious straight-line performance, to the No-Slip traction system for street-able vehicles.
  • Powertrax® offers three levels of GRIP locking differentials, ranging from the clutch-type GRIP LS with a forged steel case, the gear-driven GRIP PRO and finally the GRIP LOK for extreme traction.
  • Powertrax® = Extreme Traction Systems!
  • See More

    Richmond Gear – Differential Spool (Part No.81-1033-1)

    Differential Spool

    from

    $267.99
    Richmond Gear is the leading manufacturer of professional quality, high-performance drivetrain products. Our complete line of products ranges from high performance ring-and-pinion sets for serious street and racing applications to torque-hungry manual transmissions and components. Richmond Gear products have been winners both at the Daytona 500 and U.S. Nationals for decades. WINNERS RUN RICHMOND!

    Product Features:
    • For over 80-years, the Richmond Double-Diamond logo has represented some of the highest quality gears in the racing industry. Winners Run Richmond!
    • The superior quality of Richmond gearsets is a result of outstanding design, world class manufacturing and an extensive testing process that is performed on all products.
    • Richmond performance gearsets have been winners for decades at: NHRA, NMRA, NMCA, Daytona 500, WISSOTA and U.S. Nationals.
    • Richmond Gear is a leading manufacturer of high performance ring and pinion gearsets and drivetrain components, backed by a two year warranty.
    • Engineered to perform faster and be more reliable, Richmond performance drivetrain products are the result of a continuous research and development program combined with state-of-the-art manufacturing capabilities.
    See More

    Yukon Gear – Dura Grip Positraction For GM 9.5" With 33 Spline Axles (Part No.26025)

    Dura Grip Positraction For GM 9.5" With 33 Spline Axles

    from

    $1025.00
    The Yukon Dura Grip provides aggressive yet smooth traction to give you the confidence & performance you need. Get longer life and better traction with the heavy duty Yukon Dura Grip Positraction. The Yukon Dura Grip uses a nodular case and forged 4320 internals for added strength along with composite clutches for high performance and long life. All units are Rebuildable and many offer upgrades to increase aggressiveness for racing applications. Each unit carries a one year warranty against defects.

    Product Features:
    • Fits GM 9.5″
    • 4-spring, clutch style positraction
    • Internal gears are manufactured using forged 4320 steel and cut to provide stronger teeth
    • Fully rebuildable
    • Assembled in the USA
    See More

    Richmond Gear – Differential Spool (Part No.81-1028-1)

    Differential Spool

    from

    $259.99
    Richmond Gear is the leading manufacturer of professional quality, high-performance drivetrain products. Our complete line of products ranges from high performance ring-and-pinion sets for serious street and racing applications to torque-hungry manual transmissions and components. Richmond Gear products have been winners both at the Daytona 500 and U.S. Nationals for decades. WINNERS RUN RICHMOND!

    Product Features:
    • For over 80-years, the Richmond Double-Diamond logo has represented some of the highest quality gears in the racing industry. Winners Run Richmond!
    • The superior quality of Richmond gearsets is a result of outstanding design, world class manufacturing and an extensive testing process that is performed on all products.
    • Richmond performance gearsets have been winners for decades at: NHRA, NMRA, NMCA, Daytona 500, WISSOTA and U.S. Nationals.
    • Richmond Gear is a leading manufacturer of high performance ring and pinion gearsets and drivetrain components, backed by a two year warranty.
    • Engineered to perform faster and be more reliable, Richmond performance drivetrain products are the result of a continuous research and development program combined with state-of-the-art manufacturing capabilities.
    See More

    Most Popular Posi Units and Components for 1978 Chevrolet K20s

    Enhance your 1978 Chevrolet K20 with one of the 3 Posi Units and Components we have in stock, starting at just $259.99.

    Powertrax – Lock Right Locker (Part No.1910-LR)

    Lock Right Locker

    from

    $376.99
    The Powertrax Lock-Right ultra-strength alloy locker’s straight-line performance is equal to a solid spool, but automatically unlocks in turns. Best suited for extreme off-road to severe on-road use, Powertrax Lock Right lockers replace the spider gears in your open differential carrier using basic tools and without affecting your ring and pinion settings. The whole job can be done in your driveway in a couple of hours, pin included! Powertrax Grip-Lok, Lock-Right Lockers and No-Slip Traction Systems automatically provide 100% traction on-demand, under the toughest circumstances. The Powertrax Grip-Pro and Grip-LS performance limited slips offer smooth dependable torque transfer and traction for the best of both worlds!The Powertrax® Lock-Right Locker provides outstanding traction for off-road machines and race vehicles. Powertrax No-Slip Traction Systems deliver excellent performance to street-driven cars and trucks.Powertrax® lockers range from the original, Lock-Right for serious straight-line performance, to the No-Slip traction system for street-able vehicles.Powertrax® offers three levels of GRIP locking differentials, ranging from the clutch-type GRIP LS with a forged steel case, the gear-driven GRIP PRO and finally the GRIP LOK for extreme traction.Powertrax® = Extreme Traction Systems!
    See More

    Richmond Gear – Differential Spool (Part No.81-1033-1)

    Differential Spool

    from

    $267.99
    Richmond Gear is the leading manufacturer of professional quality, high-performance drivetrain products. Our complete line of products ranges from high performance ring-and-pinion sets for serious street and racing applications to torque-hungry manual transmissions and components. Richmond Gear products have been winners both at the Daytona 500 and U.S. Nationals for decades. WINNERS RUN RICHMOND!

    Product Features:
    • For over 80-years, the Richmond Double-Diamond logo has represented some of the highest quality gears in the racing industry. Winners Run Richmond!
    • The superior quality of Richmond gearsets is a result of outstanding design, world class manufacturing and an extensive testing process that is performed on all products.
    • Richmond performance gearsets have been winners for decades at: NHRA, NMRA, NMCA, Daytona 500, WISSOTA and U.S. Nationals.
    • Richmond Gear is a leading manufacturer of high performance ring and pinion gearsets and drivetrain components, backed by a two year warranty.
    • Engineered to perform faster and be more reliable, Richmond performance drivetrain products are the result of a continuous research and development program combined with state-of-the-art manufacturing capabilities.
    See More

    Richmond Gear – Differential Spool (Part No.81-1028-1)

    Differential Spool

    from

    $259.99
    Richmond Gear is the leading manufacturer of professional quality, high-performance drivetrain products. Our complete line of products ranges from high performance ring-and-pinion sets for serious street and racing applications to torque-hungry manual transmissions and components. Richmond Gear products have been winners both at the Daytona 500 and U.S. Nationals for decades. WINNERS RUN RICHMOND!

    Product Features:
    • For over 80-years, the Richmond Double-Diamond logo has represented some of the highest quality gears in the racing industry. Winners Run Richmond!
    • The superior quality of Richmond gearsets is a result of outstanding design, world class manufacturing and an extensive testing process that is performed on all products.
    • Richmond performance gearsets have been winners for decades at: NHRA, NMRA, NMCA, Daytona 500, WISSOTA and U.S. Nationals.
    • Richmond Gear is a leading manufacturer of high performance ring and pinion gearsets and drivetrain components, backed by a two year warranty.
    • Engineered to perform faster and be more reliable, Richmond performance drivetrain products are the result of a continuous research and development program combined with state-of-the-art manufacturing capabilities.
    See More

    FAQs for 1978 Chevrolet K20 Engine Additives

    What are the best-selling Engine Additives for 1978 Chevrolet K20s?

    Out of 3 Engine Additives that fit 1978 Chevrolet K20s, the following parts are the top sellers:

    What’s the price range for 1978 Chevrolet K20 Engine Additives?

    The prices of Engine Additives for the 1978 Chevrolet K20 range from $259.99 up to $376.99 for the most premium parts.

    What is the average price of an Engine Additive for a 1978 Chevrolet K20?

    The average price for Engine Additives for the 1978 Chevrolet K20 is $301.66. Keep in mind the variety of part types within our Engine Additive category, where you are likely to find a wide range of prices across a variety of parts and components.

    Does Advance Auto Parts sell Engine Additives for other Chevrolet K20 model years?

    Yes, we carry Engine Additives for 10 model years of Chevrolet K20s between 1975 and 1986. The following model years are the most popular for Engine Additive purchases: 1986, 1985, 1984, 1983, 1982, 1981, 1980, 1979, and 1977.

    What are the cheapest Engine Additives for my 1978 Chevrolet K20?

    The cheapest 1978 Chevrolet K20 Engine Additives we carry are:

    Does Advance Auto Parts sell Engine Additives for any other 1978 Chevrolet models?

    Yes. We stock Engine Additives for 17 other popular 1978 Chevrolet models. Some of the most popular are 1978 Impala Engine Additives, 1978 Malibu Engine Additives, 1978 Camaro Engine Additives, 1978 Monte Carlo Engine Additives, and 1978 Caprice Engine Additives.

    What types of Engine Additives do you sell for my 1978 Chevrolet K20?

    We currently have just 1 Engine Additive in stock for a 1978 Chevrolet K20, and as of 11/2/25, it is a Posi Units and Component.

    Can I get help with 1978 Chevrolet K20 Engine Additive orders?

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

    What is your return policy for Chevrolet K20 Engine Additives?

    Advance Auto Parts keeps returns simple. For new Chevrolet K20 Engine Additives and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.