OK... A little background, I have a 89 civic DX HB. I purchased a B18A1, w/trans: 91 integra axles, ECU, and motor mounts. I've converted the harnes tp MPFI I found out my B18A1 is toast... (broken motor mount on block) So my good friend gave me 2 B18B1's that appear to be newer... the valve cover is inset in the middle... Problem is both of these are missing the distributor, one's god a bent valve, and the other has a bend rod... But between the two I can get a good, working B18B1. I believe these 2 B18b1's to be OBD2a, how can I tell? The valve cover is not flat, but rather inset in teh middle... So the question is this, assuming the two new B18b1's are OBD2a, can i take the two and make one complete motor, and use my B18A1's distributor, injectors, resistor box and run it as a OBD0 B18B1? I'll eventually buy a obd2 distributor, ECU, and wiring conversion as I have another stock harness... does this make sence? Take the two dead (what i think are OBD2a) B18B1's and use the B18A1 Dizzy, injectors, resistor box and harness and run a B18B1 in OBD0 for now? How do i tell a motor is OBD1 or OBD2 Please advise, Help is greatly appreciated!