I picked up an engine and trans off facebook from a guy in Toronto, for $500 the engine was shot needed to be rebuilt ( which I'm doing slowly) plus $1,500 ($1,100 us) from Russell at sound German Automotive. I also sent him me ecu for him to flash it to run properly. The rams have a 4 plug ecu, the plug closest to the engine (4th one is green) controls the trans , what he had to do was flash it so everything else work but that 4th plug. Then he tuned it for proper fuel trim and timing. Everything else is honestly direct bolt on. The bell is the same bolt pattern the only thing I had to do was elongate the trans mounting cross meamber holes other then that nothing is different but for my 09 I have to change the Tcase because the wiring will not work but I was told by Russell that he did his truck with the 8 speed and they plugged right in. His is a 2010 . So I can't tell you forsure it will work but the difference in performance and fuel milage is noticeable right away.
The trans cooler needs to be changed from the 5 or 6 speed trans as it's not big enough if you can find the a/c condecor from a truck with an 8 speed the trans cooler is built into it as far as I was told. I just had an aftermarket one on its way for something else. Anymore questions let me know if be happy to help the best I can , if any of you guys are in the hamilton area then I'd be willing to swing by if possible.