If you want to swap in an h23, I beleive all you need is the engine, and trans. Everything else should bolt up fine. I have heard of people even using the f22 ecu without problems, but I would get the h23 one to be safe. Its an easy swap, adn you don't have to mess with the wiring harness I understand. This is not first hand knowledge on my part, just what I remeber from other threads.