Farmall A & Super A
There's not much difference between a Farmall A Series and a Farmall B series tractor.
The front end on a Farmall A is wide and the engine has been offset from center with the seat centered. The offset engine was trademarked as "Cultivision" because the driver could watch the cultivator in action.
In contrast to the A series, the Farmall B had the front end spaced close together and the drivers seat was offset to the right along with the engine being centered. For those farmers tending crops that grew taller, they had an option known as the "high crop" that let the tractor set up higher than normal. Models with this option are known as "AV" series.
When the competition from Ford increased with their innovative use of the Ferguson three point system, Farmall came out with their "Super A" series in order to meet the new competition.
The most noticeable change between the Series A and the Super A was that the Super A had improved hydraulics known as their "Touch Control" system. Previously on the Series A, the hydraulics system was known as the "Lift-All" system. The Super A had 4 cylinder engine (113 cubic inch displacement) and weighed close to 3000 pounds. The transmission had 4 forward gears and one reverse gear. The total production run for the Super A was 94,001 units.
Below are all the "Farmall A" and Farmall "Super A" listings: