My Stealths were one of the first sets.I changed spring locks and retainers.i run a .588 solid cam and the springs that came were a bit weak I hear Eddys are also.I ran comp everything.My machinsit checked them and just said the valves need a cleanup on the backcut and he is a perfectionist.He also open them up when he was doing the work.I hear the new locks etc are better than the first ones.I sold all mine to a guy and he runs them today on a milder cam.Never had a problem.Rocky