Dana 50 swap

[Scotts96sploder]

Just picked up a Dana 50 out of a 99 250. Not sure how much I’m going to beef it up, but the plan is to swap it in within the next 6-9 months. Going to probably use jeep springs and a NP205, I’ll have to have shafts made.
Obviously need hubs, gears, and a locker. Going to use a truss meant for a jeep, just to make things easy, and fab my own links.
The first piece of the puzzle is in my driveway!
I want to pull a 4r70w out of the junk yard and have it rebuilt Can I use one from another size motor, and just find the correct bell housing?

 

[Scotts96sploder]

Not explorer related, but dose anyone know what’s up with this axle? Supposedly it’s an 03 2500, but it has a Dana with disc brakes. I’m going to measure the width, if it’s close to my 50 I’m going to pull it. Just really confused because in 03 its supposed to be an AAM axle, and before that they were all 70/80s with drums.