Ok. This is my first post so please bear with me. I am getting ready to start the proccess of converting my 89' 305 TBI equiped Trans Am over to Tuned Port Injection I have everything except the wiring harness and engine control computer but while looking up the part # for the computer I noticed that the computer that is currently in my car part # 1228746 is the same as is required for the TPI setup accordong to the local parts store. So the Question is, do I only need the wiring harness for the TPI setup or will I need to change the PROM in the computer for it to work?????? Any help will be appreciated.