Ok I now know it is a MEFI 3 version GM pcm .marine use .open loop version ...anyone know where to get software for the MEFI 3 ??

Thanks Bill

Does anyone know what computer the GM crate 502 RamJet uses I have a friend coming in this weekend who can tune most OBD1 or OBD11 GM computers but he is not familar with the 502 RamJet one .....open loop, no 02 sensor and I can't tell him the service code or ??