I found a guy that sells copper hg's. I installed better pistons, but they lowered my compression to about 9.1:1. What thickness would be good to bring my compression ratio back to where it was, or maybe even higher (don't know if either are possible). I am doing a turbo later, I will put in a stock thickness when I go and put that in. It looks like he sells them in sizes from .016 to .125 (not sure if inches or mm??). Its a dohc zc btw.