long story short, wife's ls overheated, i changed the head gasket and milled the head.. ran like a champ for like 2 months, starting to crap out now. I'm just gonna throw in another motor for now and rebuild her b18b1 and throw it in a hatch and boost it later on. my question is.. aside from having to swap over the sensors (hers is obd2), would the swap from a b1 to an a1 be pretty straightforward? what else would be involved? could I use the same ecu? I searched to no avail. Thank in advance for the help!

 

There are going to be major differences, especially if it is a 90-91 B18A engine. The wiring harness and ECU are not the same. It might be closer on a 92-93 B18A engine, but, I am pretty certain it is still too different to be plug and play.