civic_hx101

I installed a 1998 Acura GSR engine in my 1999 Civic HX. It runs great, but the speedometer and the tachometer aren't working. I have an aftermarket tach spliced into the regular tach wires and it works. I tried changing out the speed sensor, but that didnt help. I have a Si ECU installed right now. I was told the P72 may fix the problem so i purchased an P72 ECU that was pulled out of a 1998 Acura GSR but one of the harnesses will not plug into it. Perhaps a jumper harness? Any suggestions? thanks