I'm not impressed with the Isky's. The outside diameter varied by up to .002 from one lifter to the next, taper and out of round were up to .0007. I sent one set back, the replacement was slightly better. It's hard to set lifter to bore clearance when the lifter size is all over the place.

Also, Isky told me I can run the EZ roll max in stock lifter bores. That was dead wrong, they bled off to much oil pressure because the cut-away area was too close to the top of the bore.