The High-RPM Hydraulic Lifters have 7,000+ RPM capability with .120" plunger travel. These lifters have a .750" diameter roller wheel for the .842" & .875" diameter lifters and a .810" diameter roller wheel for the .903" diameter lifters. The Internal tolerances are much tighter in this series. Do Not Use Oil Heavier Than 5W40! Recommended Spring Pressures are 100-225 lbs Seat Pressure and 350-550 lbs Open Pressure.
