You got an awesome deal on your axle. I doubt many people have recently rebuilt Wagoneer axles with lockers laying around waiting for a Nissan owner to buy. For many of us it's going to be a worn out 20 year old junk yard axle with nothing useable but the housing and hopefully knuckles. Stock gearing was 2.73 or 3.31 with a very few 4.10's. All 4.88 gearing has been done aftermarket on the Wagoneer axles.

On the shafts, pick your poison. Beef up the parts or risk breakage someplace very inconvenient. We shouldn't be able to break the Superior axles on 33's with our power.