If it's a J-10, it originally came with a D44. Another one of those would swap in place of the original. If you've put a J-20 D60 under it, then another one of those will swap in. Nothing else is going to be a direct swap. E350 van rear axles are pretty close in width, but the spring perches need to be moved. Anything you swap in other than the original axle will need brake and driveshaft tweaking.
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank