Studebaker WW2 history

[motto (RIP)]

I believe the US6 came into existence because General Motors could not meet the demand for the CCKW and was unwilling to go into a close relationship with another maker for parallel production of the vehicle as Ford and Willys did with the Jeep.
Many parts were interchangeable between the split diff GMC and the US6 with the biggest difference being the power plant. The US6 using a Hercules JXD 6 cylinder side valve 320 cubic inch engine whilst the GMC used an in-house 6 cylinder overhead valve 270 cubic inch unit.
A total mystery to me is why both trucks used a similar overdrive transmissions which was then cancelled out by an under drive transfer case. A similar result could be achieved using significantly fewer parts with transmission and transfer case straight through in top and high range.

David