High Energy Hydraulic Flat Tappet Lifters. Specifications .875" Diameter - 105g Weight - 2.02" Seat Height. 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: Ford Small Block 221-302 c.i.d. V8 ('63-'95), Ford Small Block 351 Windsor 351 c.i.d. ('69-'96), Ford Small Block 351C, 351M-400M ('70-'83), Ford Big Block 429-460 c.i.d. ('68-'95)