Originally Posted by Wirespokes
I tried that approach using a C clamp. However it loosened back up and added a shim instead.
A "C" clamp does not work with the late style rocker arms as the end blocks are located into the head and there is no movement. Stick a feeler gauge between the rocker block and rocker arm to figure out how much play you have. Take that number plus the thickness of the shims that are already there to figure out what combination of shims you need. I agree- the fewer the better/easier