Designed for engines that oil through rocker shafts, these .300" taller Solid Roller Lifters from COMP Cams are engineered to withstand the demands of aggressive cam lobe designs and increased RPM ranges. They feature a wear resistant tool steel axle, precision sorted needle bearings and EDM Oil Injection Technology that guarantees the bearing assembly receives a constant flow of oil. Endure-X Solid Roller Lifters are heat treated, machined to ultra-high tolerances and fully rebuildable.