This series of pictures shows an SM420 transmission mated to an FJ40 "3-speed" transfer case using a plate adapter from Warden's Auto Repair (web page here). The case of the SM420 needed to be modified to accommodate the front output flange. The resulting clearance is measured to be about 0.012". The flange still needs to have about 0.050" removed from the perimeter for better clearance.

Note that the transfer case is rotated downward about 6 degrees. This is more easily seen in the rear view.