i have read the posts over and over and cant get clear info. i have a 99 g20t and want to swap in a u12/u13 bb. and no i do not want to turbo my motor. i know what to do for everything except wiring\ecu\harness\repin\etc. what do i need to do. no one has clearly stated whether to use my factory ecu and get it programmed or to get a 95-97 ser ecu and get it programmed and repin\harness etc. please help everyone, it would be greatly appreciated if some one could clearly explain what has to be done. thanks eveyone.