Could be the same. You need to check if either rearend is a sure grip. They are different length axle shafts on sure grip and open axles in the same car. Difference is the center pin width in the differnetial. Difference in length is 1/8" per axle shaft. You can shorten and axle shaft on a lathe.

If both are open axles, they will swap.
If both are sure grip axles, they will swap.