the main differences are that obd2 has an electronic throttle body, and thus a different inlet manifold, and also has single row timing chains. but i think theres a few other bits and bobs on the engine, wiring/sensors as well. but if you used the inlet, engine loom, and anciliaries from your original engine theres no reason why it wouldn't work in my mind...but i've never had a good look at an obd2.