the corvette rear end is 62.5 in wide but i dont remember how wide the rams is

 

There are a lot of ideas available, pick what works best for you and go with it. I would gather parts and build it as a assembly right down to the clutch components and emergency brakes. Mock up the drive pieces (bell housing) using a spare engine block. Then when it is complete and ready to go lift the bed and perhaps the cab and finish the build. I don't know what that rear trans/axle assembly costs, but my guess it looks like a $15-20k project. Maybe $5k more than a Viper 6 spd conversion would cost. Anyone have the cost of the corvette trans/axle?