Several people have said that the 3/4-tons only had 4-speed trannys, but the standard transmission for the AD 3/4-tons was the 3-on-the-tree, with the 4-speed as an option. The 1-tons had the 4-speed as standard.
The enclosed front driveshaft on the AD 3/4-tons ended with the '54 models. All of the AD 1-ton drivelines were fully open.
