Some have done it.
I just picked up another 5.7 core for 500.00 Canadian With wiring harness and computer.
Their out there.
The 4.7 ECM has been done but to what extent I do not know.
But HP supports 04 to 10 Ram and Dakota.
Cant see it being that difficult. They say 05 ECM are the best and easiest to tune. Soooo get an 05 Dakota ECM and youy keep the throttle cable.
Dakotas Durangos .com has lots of info.
The reason I want to use the 4.7 ECM opposed to the 5.7 is that I live in an area that requires smog testing.
So no cel light equals a pass.