There's a decent amount in the spec to make up differences. Forget what I read, like 55 thou? When I pit in new lifters, tightening rockers I seen valves open that should have been shut. I thought crap, cause I had valve job and thought maybe they didn't take enough off top of the stem. So they were very tight, couldn't twist them. Rotated engine couple times by hand and the same valves I could now twist, but no lash. Engine runs quiet now too.

First 5 minutes sucked though, lol.