I wonder if it's an option to try first by ask the dealer if they can reprogram on your truck with a program that's used in 2014 Ram 3500 with AISIN auto trans? If I recall correctly on some forums some guys with the manual, they had dealer to reprogram them to bring the power level up to what's found in trucks with the AISIN trans.
2014 Ram 3500 with AISIN 385 hp, 850 ft-tq
2014 Ram 4500 with manual 320 hp, 650 ft-tq
2014 Ram 4500 with AISIN 325 hp, 750 ft-tq
If the dealer will do that for you, that'll pretty much means a 65 hp, 200 ft-tq increase for you!
Just an idea if it'll work to have the dealer to reprogram your truck and not void the warranty and possibly cheaper, or free if you can talk haha.