Full-travel hydraulic lifters made from machined steel designed with .200" of travel Exceed the needs of large-lift camshafts and higher spring pressures with a slower bleed-down rate Maintain proper and critical oil flow to valves, springs, rockers, shafts and valve guides Increases engine RPM and valvetrain stability; decreases valve float for maximum valve lift Recommended for both strip and performance street engines Made in the U.S.A. High-volume oil pump recommended. Recommended for engines running higher than 185 lb (84 kg) valve spring seat pressure.. LIFTERS RS EVO 85-99