COMP Cams High Energy Hydraulic Flat Lifter Set for Buick 350-455 and Cadillac 472-500

High Energy Hydraulic Flat Tappet Lifters. Patented orifice metering valve precisely meters oil to the Rocker arms. Continuous contact between the metering valve and Pushrod seat is maintained: Eliminating excessive oiling at high RPM. Pushrod seat is made of a special powdered Metal iron alloy that is heat-treated for strength and wear resistance. Longer piston than conventional hydraulic lifters, which provides more load bearing surface and increases lifter longevity. Lightweight check valve disc allows for quicker response, which results in increased engine speed before valve float. Lightweight check valve disc maintains added control at all engine speeds and loads. Applications: Buick 350-455 V8 ('67-'80), Cadillac 425-500 V8 ('63-'79). Specifications .842" Diameter - 98g Weight - 2.05" Seat Height . Flat Tappet vs. Roller Tappet Lifters. In nearly all circumstances, a good Roller Camshaft design will outperform its flat tappet counterpart. Among the benefits of Roller cams are higher tappet velocity, more lift and more area, along with reduced valve train friction (often a 20+ HP increase) and higher engine RPM with little effect on low speed drivability and power.