Any SM 420 transmission can be adapted for torque tube vehicles by changing the rear bearing retainer casting which has the pivot for the torque tube ball. The tricky part is finding the front half of the universal joint which bolts to the transmission output shaft. Those items are very scarce. Making the torque tube from a truck that was originally equipped with a crash box transmission fit the 420 transmission might require some fancy footwork, however. I seem to remember some trucks that had a short torque tube, and then an open driveline to the rear end, which might be one possible option.
Jerry
