You will absolutely not be able to use a 2007 TEHCM in a 2012. The TEHCM has to be correct for the year and the valve body has to match the TEHCM. You need to use the entire 2012 valve body and TEHCM in your 2007 transmission but swap the speed sensors from the 2007 valve body. Since it’s already programmed to your truck, it’ll work without programming but you do need to reset the shift adapts pretty quickly.
Ok that's what the Facebook responses were saying, but they didn't mention the sensors or anything. The speed sensors are both pieces with wires? So take those from the 2007 valve body and put them on the 2012 valve body. Then put the 2012 valve body with 07 sensors into the 07 transmission? I think I got it. Thanks everyone