Like Dan said, you might have apples and oranges. Since your going after the headgasket, replace the valve cover gasket at the same time.
You may not need machining, but machining a little off will increase your compression giving a slight boost in power. For $100-$150, smart thing to do while you are in there. Read Idahodougs thread, he just did it while he was in there.
You may not need machining, but machining a little off will increase your compression giving a slight boost in power. For $100-$150, smart thing to do while you are in there. Read Idahodougs thread, he just did it while he was in there.