Well I recently bought a set of Dana 60's out of 84 Dodge W350. Turns out the length of the axles are almost exactly what the stock rear axle is in length and the spring perch mounts for the rear axles is the same as my stock one (44in from centers). The front axle's perch mounts are 33in if I remember correctly. I also traded my set of allterrain 33x12.5 R15 for a set and a half of goodyear wrangler 37x12.5 R16.5 with rims.

Next step gears....