Well I built a Y8 motor to put in my 91 Civic. It has SRP 10.5:1 c/r pistons. I found out today that the head is actually a p2j-1 D15Z6 head. Can anyone tell me what the compression will be?

All the calculators I find don't have a option for the D15Z6 head, only the D16Z6

 

are u sure its the D15z1 head instead of a D15z6 i've never herd of that

 

Yes it's a D15Z6 head. It was a d series motor in Europe