I've seen some crude but effective adapters made from heavy walled pipe and a few slabs of 1/4" or 5/16" flat plate --they made the plates bolt up to the transmission tail and the transfer case (by tracing the bolt patterns and shape of the original adapter and tailshaft housing
),then the trans and T-case were bolted to the engine and crossmember, to determine the length of the pipe,and it was cut to size with a pipe cutter to keep it square,and tack welded in place to the plates--then taken off, and fully welded on the bench vise ,holding the parts in line ,all the way around..
One guy I know did this when he made a tractor using the drivetrain from a chevy 4x4,after another friend saw what he did,he adapted a 2wd TH400 into his pickup the same way and it worked very well..he already had the transmission,and a NP-208 T-case with the 32 spline input..