The only diffs are p28, pr3 vtec ecu, or controller. If you are already obdo, its cheaper to go with a vtec controller. Otherwise, you will need to have a vtec ecu + hasport obdo to obd1 conversion harness (unless you get a jdm pr3), z6 distributor, z6 injectors + some white to grey plug swapping thats going to require an obd1 harness, AND an obd1 4wire o2 sensor+ the 1 to 4 wire o2 sensor conversion. For the price of all that crap, you can get the mackdaddy of all vtec controllers for yours, and a couple of your friends rides! Not really, but close. Im going to get my hands on either a pr3 or a controller.