I'm getting a good deal on a gsr head but i'm going with high boost and i hear that the gsr head gives more compression.Would it affect me with like 14 psi?

 

GSR head has a smaller combustion chamber than the other B-series (B16A/B18C5) head resulting in a slightly higher compression ratio when used with the same pistons. You mention your going with high boost, so I'm assuming your not re-using the OE pistons. You can get dished for flattop pistons to give you pretty much any compression ratio you want.