Hi eveyrone. I have a harness and ECM from an 8.1L. Finished modifying the harness to find the ECM is no good. I have a spare P59 ECM from an 04 Yukon with 5.3L. This engine combo is going into a 69, so no electronic gauges or anything to worry about working. I am wanting to take a stock 8.1L file from the repository and segment swap it into the 5.3L ECM. Is this likely to work, or am I going to have to write the whole file? I would like to avoid that as it would double my licensing cost.
Thank you.