one more question... if you had a 94 gsr (b18c1-us spec) and you replaced just the shortblock with a complete 00' US spec ITR block, what would your compression be. I know the gsr has 10.-to-1, and the type r has 10.6-to-1. The gsr head would create more compression right, that should be correct. So that SHOULD make it like 10.8-or 10.9 to one right? B/C I know that when you put a us 00' itr head on a gsr it lowers compression on the gsr from 10.-1 down to 9.8-1. Anyone know about this stuff? Also anyone used a sppon or mugen headgasket that raises compression. Any favorites or reccommendations.