1974 barracuda 5.9 swap efi

i guys ! bought a dakota r/t rwd and im about to swap everything in my barracuda that is 360 and 4 speed 8 3/4 3.23 , even thinking adding the oem cluster of the dakota in the car and the 3.92 suregrip 9.25 but need to swap the axles to a 5 bolt 4.5 bolt pattern , the only concern is fitting the 46re and cut the floor , and to make a custom driveshaft for the car , if you guys have some advice or tips ill apreciate it a lot !!!