On my 327, when I changed the valve cover gaskets (felpro #1404 i think) and tighten down the valve cover bolts the roller rockers hit making a knocking noise. If I back the bolts off to make the noise stop they leak oil. Also the valve covers hit the boss on the intake (team g). Any ideas? ??? Thanks, Pete One more thing...what is a good spark plug to use? Mild cam, intake, carb, headers