integra321

I'm trying to get my car BAR'd and I've got a B16A2 from a 00 Civic Si in my 95 Integra which is OBD1. I am wondering how hard it would be to swap the wiring harness (the whole thing from the engine bay to the ecu) into my 95 Integra. I've heard the one from the Civic is a one piece and may be difficult to install, but I'm just wondering if there is anybody who has experience with this and how hard it would be. Thank you.