I've replaced my B18C integra GSR head with B16A (Honda Civic SiR) head which fits quite well. My questions are what's the different between B18C and B16A wrt to cam, compression and performance. I've did measured the cam diameter for both B18C and B16A but couldn't see any difference at all. Suggestions are welcome. While on different subject, does anybody know how much the Endyn piston and con rod for B20 cost?