Does anybody happen to know how much you can safely deck the block. I want to raise the cr and can't find any info on this. I want to shave off .020 witch will give me about 10.34 :1

 

I wouldn't deck the block unless absolutely necessary, the pistons stick up out of the blocks already. I would mill the heads to get the compression you want.

 

I think there is .008 clearance if what I read is correct. So milling the block would be out of the question for anything more than just cleaning and making it flat. If I were going to mill the heads could I take .020 off with out having intake alignment issues or valve clearance problems? I did read that people have done .020 on a ls6 but I think they use dished pistons too. L33' have flat top pistons so it may not work.