ATK GM 383 Stroker 500 HP HP55 Stage 1 Aluminum Head

ATK HP55 500 HP High-Output Crate Motor

ATK GM 383 Stroker 500 HP HP55 Stage 1 Aluminum Head engines offer an elite high-output crate motor configuration for high-performance street-strip applications. Featuring massive aluminum cylinder heads on a seasoned cast-iron block, this 383ci stroker is engineered to produce a verified 500 horsepower, making it a perfect high-performance fit for the Chevrolet Camaro, Nova, or Corvette. The assembly maintains superior valvetrain stability via a precision hydraulic roller camshaft, delivering exceptional low-end torque and high-RPM power in a traditional Small Block Chevy architecture.

This Stage 1 remanufactured long block foundation arrives in an un-dressed state, giving builders the freedom to select high-performance induction and accessory components to support the 500 HP output. While the ATK HP55 includes essential foundation items like the oil pan and valve covers, it is also backed by a 1-Year professional warranty to ensure long-term structural reliability. This elite-level stroker is the ultimate choice for enthusiasts demanding extreme performance and professional assembly standards in a classic GM chassis project.

Key Features of ATK High Performance HP55

• 6.3L 383ci stroker displacement delivering 500 horsepower.
• High-flow aluminum cylinder heads for maximum volumetric efficiency.
• Hydraulic roller camshaft ensures consistent valvetrain stability.
• Internal and external balance configuration for smooth operation.
• Seasoned cast-iron block foundation for superior structural strength.
• Backed by a professional 1-Year limited warranty.
• Includes pre-installed oil pan, valve covers, and timing cover.

HP55 Include:

• Oil Pan
• Valve Covers
• Timing Cover