I'm not certain, but I think the B16 heads have a smaller compression area. Basically, your compression is greater than with the B18C1 heads. Higher compression, generally more horsepower. However, if you got the B18C5 (Type-R) head, you'd have that and a factory port job, which is the best of all. Not to mention if it came with the Type-R valvetrain. I guess another popular combo is the CRVtec, where you get the benefit of increased displacement, with the vtec, better flowing heads, etc etc.