COMP Cams 2900-1 Performance Series Solid/Mechanical Lifter for Small and Big Block Chevy/Pontiac/Oldsmobile/Cadillac 0.842 inches diameter; 86 gram weight; 1.88 inches seat height Includes precision-ground crown radius and surface finish to promote performance camshaft compatibility and high-rpm durability Lightweight design and premium one-piece pushrod seat provide extended rpm range Features precision-machined and accurately located oil band to yield a consistent, properly metered oil flow Designed for elevated, race application valve spring pressures