dont use that stock felpro blue head gasket it isnt good for anthing over .020"go with the felpro marine/hiperformance gasket i forget the # don'tfix what aint broke just run it. rings won't effect piston rock only worn out cylinders and pistons .if you hone it you'll probably see if it needs to be bored i built 2 400's one of them is 060 over and no problems although it is a 1970 which seems heavier than my other one that is a 1978.don'tworry about ialittle piston rock shove tite lobe sep.cam in it and have fun