That's a good looking header you got there! Should last a long time.
It is a common practise to pound the valve tops with a hammer (seating and depressing the spring 1/4 inch or so) after all are back together... Making sure the keepers are in position as they should be. We don't want one of them dropping onto a piston from a poorly installed keeper.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

professional bovine relocation specialist