COMP Cams Performance Series Solid/Mechanical Lifters With EDM Injection Technology are premium lifters designed specifically for high-end street and race applications. Built to extreme precision tolerances to create the most durable solid lifters available, Performance Series Lifters are engineered to handle elevated, race application valve spring pressures. Each lifter features a precision-ground crown radius and surface finish to extend high-rpm durability and promote compatibility with performance camshafts. The .012" EDM oil hole in the lifter face increases oil flow to the lifter face to camshaft lobe contact point. These lifters are designed for Small Block Chevy, Big Block Chevy, Oldsmobile V8, Pontiac V8 and Cadillac V8 applications.