It really all depends on what compression your shooting for... I put b16 pistons in my gsr, and i had to get the head shaved, and I didn't want my compression over 12:1 so I sold the gsr head and got the b16 head instead. Plus, b16 head's have better flow... so i've heard. Also, I am running the itr valve train with a port and polish, so IMO.... B16 FTMFW!!!!!!!