[Ggmac]

Your vale reliefs in head look much more shallow than a factory set of heads . Your fear of low compression may be made up by those shallow valve reliefs . Im just looking at a picture but had the factory heads on the bench today . The only way to tell is to cc them and compare to factory .if it ran with the flat tops it should run better with these pistons. Did you ever take a compression reading with the flat top pistons and these heads ?