My friend has this setup d15b7 with a crx si head. His first and second gear runs okay, but his third gear kick *** you know. He can hang with gsr in high end. He only has intake and exhaust. I thought crx head don't fit, but it did.

 

D series heads are interchangeable with any D series heads..but whats your question??

 

heads are about the same cam must be alittle better..