wrenchtech, the gear helix angle on the longer input and countershaft of the 96' and newer R150 is greater and will not interchange with the earlier shorter input gearsets 
Marlin,
How about a Taco tranny behind the Supra bellhousing with a Marlin Crawler t-case adapter ? Input shaft length is about the same, spline is the same as the R154; right?
Matt
