Race Hydraulic Flat Tappet LiftersTighter plunger-to-body tolerances and premium one-piece Pushrod seatsSuper strict tolerances for the Mechanical internals optimize performanceExtra heavy-duty snap ring design increases lifter strength and durabilityPre-load can be set between .000"-.030" Applications: Ford Small and Big Block Specifications .875" Diameter - 122g Weight - 2.01" Seat Height.