Short-travel hydraulic roller tappets give increased valve train stability at high rpm This offers maximum HP and valve train durability, especially with modern camshaft profiles Features a rigid nodular iron body and a premium 52100 series steel alloy bearing, axle and wheel assembly Premium materials last longer and provide a stronger tappet Utilizes an advanced ultra-high flow metering system which allows more oil movement through the engine to aid in cooling Each lifter is precision ID Ground and matched with a Graded piston, ensuring reliable pump-up and quiet operation Drop-in replacement for stock tappets Made in the U.S.A.. TAPPET HYD SHORT 99-21 BT