I poked around a little looking for a compatability matrix for the ECM/TCM combo, I found it once but can't find it anymore, I think it was with a pedal/tac/ecm list as well, very handy but can't quickly find it. You might try the HPTuners forum as well.. actually that might be where those lists are...

 

I have HPTuners, yes. If you have notes on the wiring and are willing to share that'd be helpful, appreciate it. Thank you both for the information, this has been helpful getting me up to speed on what it'd take to get a gen4 harness to work with my project.