The heads that I had were missing a few of those hardened shims under the valvesprings...My machinist couldn't believe that they were like that and made a point to get in contact with edelbrock about it. So it does happen.
Well there ya go.. I assume you are happy they were checked out first.
BTW, I don't think the standard shims are hardened at all; I can bend them by hand, and they look like plain-jane spring shims. But they function to spread to spring load around evenly. Edelbrock does have optional spring cups; I have not figured out when they should be applied but I assume it is when you go above a certain spring rate.....??
