Transfercases

I have a 23 spline, 4x4 AX15. Will a transfercase from behind an auto bolt up?

I was thinking they were the same but while looking for some on a search site, they had seperate searches for auto trannies and manuals. Now I'm not sure.

depends on the year, the AW4 changed over from 21-23 spline in the 91 year. so a 1990 will be a 21 spline case and a 91 a 23 spline.

there has been some discussion of long-input and short-input but i've seen like 5 of them, and never noticed a difference in them so idk jack about that.