And for those reading, it was indeed PCM of NC I talked to, and they specifically did all the hard work figuring out just for the GTO/ TBSS to 4l80 conversion. And they chose that instead of 'regular' E40/T42 because of some things specific to that combo. The amount of hours and dollars quoted that they spent to figure it all out was incredible... which is also why they won't bother doing it all again to try and make the other E40/T42 combos work. Can't blame them lol. I, of course, have the regular non TBSS stuff I don't mind going another route, it just would have been nice if it was easier.

 

If you have an E40/T42 and wiring harness from an automatic car, All you need is the PCM of NC conversion harness and relay harness. Hook up the rear ISS plug. Change the gear ratios in the trans tune, change the shift points (you can look up a 4L80 tune and get the numbers) . Everything works including cruise (05 GTO). If the ECM is from a stick shift vehicle, you have some more work to do---send it off to get the OS changed to a auto and paired with the T42. Make sure and use a 4L80 that can mount the electric shift indicator on the side. They have the screw bosses and longer shift shaft.

 

I actually called and personally talked to PCM of NC. No, it can not be done in my situation with their products. If I had a 58 tooth reluctor wheel and a TBSS PCM, then i'd be on the right path. But I don't.

 

Seeing as how they actually sell the conversion adapter that allows exactly what I said to do I'm not sure why they would say that. And again, I've done it more times than I can remember at this point.

Correct.