You can break in new lifters on an old cam, but not old lifters on a new cam. And check the rest of your valvetrain for wear before you go replacing lifters. Perhaps cleaning the gunk out of the lifters may help. Are they hyd lifters? What year is the engine?

chip


Preaching the Hot Rod Gospel according to the 4-stroke apostles:

Suck, Squish, Fire and Fumes