It looks like you have both trucks already, so I would grab a soft tape and pull some measurements to see if things on both trucks match. If everything measures out to be the same, then things should swap over. I would measure distance between bumper brackets, length of fender front to back, distance between front wheels, & stuff like that. As Far as swapping motors, the 4.0 should fit but you need the transmission too, and the wiring harness.