As I have mentioned before, I sold my Model 75 from Radiator back to the 4 speed transmission
to Jeff Cromeens some time after his fire. It might still be around. I would guess that without overdrive, it would have had a much lower rear end ratio for easy cruising in high gear.
At the time, I had my brother, the tractor mechanic, take a look inside. He was impressed by how substantial and well-built it seemed. Later Ford trucks used a four speed. Doubt if there was any influence on that design.
Later, in 1970's, Ford made a version of its top-loader with an overdrive in 4th gear. It doesn't have much of a following today, everyone just went directly to 5 speeds. In the 1980's I was driving K-cars, and I converted a couple of them to later 5 speeds. Made them much more sporty.