Originally posted by "CronicBurn"
not to second guess you, but it's in my nature... a couple cc's is a LOT... Where did you get this info from, I would like to know more about it. I wasn't aware changing a head would change the displacment of an engine.
Changing the head does not change the displacement (as displacement is determined by the bore x the stroke). However, it does change the compression ratio. Now, a gsr head does have a smaller combustion chamber than the b16a head. From what I'm reading, the gsr head flows pretty well, and better than a b16a head if both are ported and polished. Since the GSR head has a smaller combustion chamber, it will yield a higher compression ratio. I know that the compression ratio would be raised .2 on over a b16a head on a b18a/b block. So if you put a b18c head on a b16a block, it would raise the compression.