I did a 5" TG SAS swap on a 1987 "7-Runner" and I have two friends with 4" TG SAS swaps and both of them had a drive shaft made with long travel splines. I tried to run one of there drive shafts and its Way to long, "neither of them have dual cases." nor do I. I moved my front hanger a 1/2" more forward than theirs. I'm kind of stumped on why my axle to xfer case would be a shorter distance than theirs?

 

wonder if someone swapped in an L-series transmission from a first gen,
L43, L45, 50,52 transmission are 4" shorter than the W-56 that should be in your truck.

Does it look like your crossmember has been moved?
Pics would show a lot

 

I know for a fact it's a w56 because I put a bellhousing off a 7mge and I took my trans into to get it rebuilt. the mount is stock and not moved or tampered with.