COMP Cams 867-12 Pro Magnum Hydraulic Flat Tappet Lifter Set - 12 Piece

The COMP Cams 867-12 Pro Magnum Hydraulic Lifter Set is a high-performance, 12-piece hydraulic flat tappet lifter kit engineered specifically for AMC 6-cylinder 199-258 engines. Designed to push past the RPM limits of conventional hydraulic lifters, these lifters are an ideal upgrade for performance builds and race applications where a hydraulic lifter is required.

Standard hydraulic lifters suffer from internal piston misalignment at elevated RPM, causing the lifter to "pump up." This harmful condition leads to valve damage, power loss, and potential engine failure. The Pro Magnum design eliminates this problem by maintaining proper internal piston positioning at high engine speeds, resulting in more consistent valve control and a significant power gain over stock or standard performance hydraulic lifters.

Key Features:

• Hydraulic Flat Tappet Design — drop-in hydraulic lifter upgrade for AMC 6-cylinder engines
• High-RPM Optimized — internal piston geometry prevents harmful pump-up at elevated engine speeds
• Significant Power Increase — outperforms standard high-performance hydraulic lifters, especially in race use
• 0.904" Lifter Diameter — precision-machined to OEM bore sizing
• 1.84" Seat Height — correct geometry for AMC 6-cylinder valvetrain
• 107g Lifter Weight — optimized for responsive valvetrain feel

Installation Notes: An adjustable valvetrain is required. Set lifter preload to 0.002"–0.004" with the engine at operating temperature. Different length pushrods may be required.

COMP Cams Pro Magnum hydraulic lifters are the go-to choice for performance enthusiasts and racers who demand reliable high-RPM operation without sacrificing the convenience of a hydraulic lifter setup.