318willrun i hear ya !!! Ahahah but how do you make the compression go up ? I have to go to a machine shop but dont even know were to start . Since the pistons are plain jane 30 over , the only way is to mill the heads right ?
Well, 318's are "advertised around 8.5 to 1", don't mean your there, though. How far the pistons are down the hole, and the CC's of the heads will determine that.
Means your .030 over, that will gain you compression, but what pistons did they use??? If they used a flat top piston, and they are no further down the hole than the factory, that may be enough to get you a true 8.5 to one.
Yes, you can cut the heads .040 and gain close to a half point..... IF you use the same thickness of head gasket as the factory used.
only true way to know the compression is to measure heads and short block, don't forget the head gasket thickness.
A true 8.5 to 1 compression is plenty to perform on the street with pump gas.