feistyfeist

I have a 71' olds with a 350 rocket. I just rebuilt the engine, but my dad ordered the lc pistons. Well, the #8 went out so I pulled the head and decided I should try to increase the compression by planing the heads. I have a mild cam, with 270 deg duration. How far can I plane the heads before I get into trouble? I would like to bring the compression to 9 to 1. If anyone has any expierience please shoot me a thread.