I am running a 2016 6.2L EROD Crate motor with the E67 ECU and a 2014 6L80E which I believe has the T43 TCM. It was not easy to make this transmission want to allow the HP Tuners to talk to it. Thank god for nerdy engineers and super smart guys that have nothing better to do. If I were to do it over again from what I have learned I would go with the E38 ECU and a 6L80E from anything other then the 2013-2014. There were some changes made to the harness on the 2013-2014. Any of these combinations most likely will work if you have the knowledge and some support from guys that have been down this road. I will say from what my builder tells me that all the headaches and hours spent trying to make it work together was worth it. He doesn't want me to pick up my cruiser (says he want's to keep it) and it drives like a dream. The combo 6.2 w/ 6L80E is near perfect power and the transmission he says is geared perfect for this truck with factory 411 diff gearing. It is around 1800 RPM at 70 mph in 6th (0.667) and 1st gear (4.027) he says gets with it. He ran my heavy beast against his 2016 GMC 2500 6.6 Diesel and claims the 80 series walked on it. I wasn't going for speed or HP just reliable and solid power for offroad and pulling trailers up steep grades in the mountains. He says mission accomplished. I look forward to driving it and I hope it stays reliable like it was in the past.