I just had IWE install an ARB in my 74's rear 3rd. I dropped off the removed 3rd and supplied the locker. My bearings were fine and re-used. They supplied a crush sleeve, pinion nut and seal.
I would guess if you're driving your truck in open and leaving with it locked you'll be looking at least $4000 with a compressor.
Sure wish I'd held out for a 74 with lockers now that I decided to keep my 70 for a bush pig. Oh well...