S&S CYCLE 0929-0004 33-5352 Hydraulic Tappets - Evolution Big Twin | XLFeatures 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 controls oil delivery to top end, ensuring rapid lifter pump up and