my friend is selling me his b18c5 block for 300. it needs to be rebuilt because he blew it a month ago..i was wondering if it is good idea to built that type r block and maybe put some ctr or pr3 on it...and slap my gsr head with it..i dunt wanna bother building my own block bcuz this is my only car and i need it while i go to school..im thinking doing this might drop my cmp.correct me if im wrong...but has anyone done this b4??....never seen it my self so i need help...THNX

 

GSR head raises compression because of Pentroof and smaller combustion chamber. I could be wrong, but even with stock ITR bottom end rebuilt and the GSR head it might raise compression, but I'm stupid ya know.

 

gsr head does raise compression on the c5 block. I would keep the block at oe compression...perhaps bump it up a little with hi comp vavles or thinner head gasket or both rather than running a ctr piston.....just an opinion..personal preference i guess...

my 2 cents