How Much can these heads be safely milled? I am wanting about 11.0 CR on a stock ,4.030 bored, 6.0. I am also thinking about MLS head gaskets. What thickness should these be? I figured milling is a cheap way to make power. and while some have said that My 706's will work on the 6.0... For like $50-$75 a head I can mill the 317's. But Can I get My 11.0 CR goal? And is this CR too high? I run 93 octane fuel.