S&S HIGH-PERFORMANCE TAPPETS (EVO & XL)S&S HIGH PERFORMANCE TAPPETS A must when doing any performance cam upgrade Rollers have a larger than stock inner bearing race that reduces stress and increases axle life Each lifter body and plunger assembly is hand fit and pressure tested to ensure correct operation Redesigned plunger assembly withstands forces associated with heavy duty valve springs and pushrods typically used in high performance applications Revised metering device precisely