My 93 sidekick had a obdII motor put in before I bought it. I believe it has the old distributor on it, and it seems to work fine, except that to get the timing near factory specs, you have to have it all the way at the end of its travel. Taking it out and turning it one cog over doesn't help, because then it is at the end of it's travel the other way.
The wiring harness was replaced and matched to the motor, but the ECM is original. There was just a plug where the crank sensor was in the oil pump, and the wire that went to the sensor is just floating free. Since the computer doesn't know it's there, it doesn't matter.
Not sure about the injectors.