I haven't put many hours on my new motor, but I though after I run it this weekend I'd check at least some of the valves. Motor in this case is a bbc with a bullett solid roller. I guess my main question is the cam card says "hot" lash is .020 intake, .026 exaust. So would those #'s be the same with iron or aluminum heads?? I don't know why that sounds loose to me. I guess when the motor is cold those lash #'s will be smaller/tighter?