Axle swaps for dummies...help!

Hard to comment without knowing more about it. Locker? If so what type? Disc brakes were an option in '76 so are they stock or something else? Gear ratio? Complete? What type locking hubs if any?
Lots of variables here especially since it's a modified Jeep (Dana 44 not stock in '76)

 

He sent me some pics and info. Disc brakes, 3:73s, all seals and bearings have been replaced. I'll post a couple pictures tomorrow that he sent

 

What is he asking for it? Condition of ball joints and brakes? Is it still set up for spring under or has it been modified for spring over. I bring this up as things to consider.

 

Well that guy never got back with me...found a couple that are within a few hours drive and they are willing to meet half way. One with discs one with drums. The one with discs has Sears lockers on it...that was definitely before my time haha. I'll post pics in a bit if I can.