I am a true newbie to much of the OBD1 coding and prom changes. I have been working on and tuning cars and bikes for several decades now, just haven't had the need to get an closer within the ECM other than changing harnesses, or merging a few harnesses. Wiring and sensors don't intimate me much, the software is another animal!
Currently I'm going through a '89 GMC K1500 with a stock 350. Truck originally had an automatic transmission, and transfer case. Now that same truck has a manual 5 speed with the transfer case. I'm under the impression most everything can remain the same, other than a signal to the ECM if the truck is in Park or Neutral, and the TCC circuitry. Will it be a simple matter of installing a pre-programed chip into this ECM, and cleaning up some of the wiring, or is there a bit more involved? BTW, the ECM in this truck is a 16125851 ANLW.
Thanks in advance to whatever direction I may be guided!