hopefully that 83 axle works out. doesnt that have the vacuum disconnect?
1980-1983 Wagoneer, front dana 44 and rear AMC 20 (it is NOT the weak 2-piece axle type) they are fullsize width axles. The 84-85 grand wagoneer is the one your thinking about, even with those its easy to delete the vacuum disconnect from it.
36/37 tires would be about the biggest I would put on a dana 44. You swap to better axle shafts maybe 38/39. Heck I like overkill any only have 35s for my dana 60s but I have a lot more engine going in mine.