just cc,d my heads will this be too much comp. ?

krenzy_84 said
Hi I have a set of 1970 U heads for my 69 340 I will be putting in my 72 duster. Just did a cc check and I cam up with 65 CC heads have a stamp on them of 63.4 cc I would assume this was not done at the factory but by a machine shop. I have sealed power L2316 pistons bored 40 over. My question is will I have too much comp. for pump gas with these heads? I know the pistons are factory 10.5 to 1 and that is with 72 cc factory x heads I assume. any knowledge on this will help as I don't want to have a race fuel only engine.

You need to be out of the bore .017-.018 just to hit the factory mark.

Usually you need to be out of the hole a bit more to get the CR up to 10.5:1 like you want. It's nothing to be .040 or more out of the hole.

At 65 cc's you may get lucky and only need to be out .020ish but I'd need to do the math.