Decided to knock the dust off this old project! Back in about 05 or 06 I worked with a few guys on thirdgen doing an upgrade from the old reliable ECM 8746/7747 to the later 95-95 TBI truck PCM. These are the same PCM I just used in the MPFI install. There are several versions used in TBI trucks and CPI trucks and vans with the 4.3. The main ones are the 8625 and the 7427. There are code difference in each application but all of them can interchange. Back when I did this I was just looking at the latest hot thing. But at the time it just didn't seem worth it with all the ECM's avail and they still work perfectly fine on our old motors. So I didn't feel it was worth doing a writeup at the time. Well since I am using this PCM for the MPFI I figured I would show some of the versatility it has. Back then I made this little crossover adapter so I can simply plug the new PCM into an existing ECM harness. This adapter isn't needed and actually takes more time to build then just swapping pins on the harness. But it does allow me to test ECM's, PCM's and chips in the same vehicle. The big advantage and disadvantage to this PCM is amount of code it has. There are so many tweaks that can be done that just about any mod you want to perform, it can handle it. Electric fans, wide band O2, turbo, electronic overdrive tranny....etc As I get time I will be documenting most of these in my various project builds. I'll also be adding all the pin changes required to swap this in. So stay tuned as I progress through some of my projects. First the adapter I made: With the PCM plugged in. Plugged into my old 72 TBI travelall. Using Tunercat to log a little data and make a few changes.