S&S Hydraulic Lifters For Harley Features: .123 larger in diameter than the raceless roller axles currently used by some manufacturers Improved inner race-roller design allows use of more, and larger bearings to increase load-carrying surface area, further reducing stress and wear in the critical roller area Redesigned plunger assembly better withstands forces associated with heavy-duty valve springs and cams typically used in high-performance applications Improved metering device precisely controls oil delivery to top end, ensuring rapid lifter pump-up and reducing possibility of oil starvation to bottom end Each lifter body and plunger assembly is selective-fit and then leak down tested to ensure correct operation The Hl2T Limited Travel Kit for improved cold starts and high rpm valve timing accuracy Kit of four tappets