Shown below are pictures of the Model A transmission which is rebuilt by Mitchell Manufacturing using all new internal gears and 2nd and 3rd gear synchronizers.
A 15% higher gear ratio is also available. The resulting transmission has many desirable similarities to the 1932 Model B transmission, without having to install a Model B engine and transmission in a Model A along with the necessary wishbone and pedal mounting.
Shown above is the view of the reworked shift tower with the new forks and shafts as assembled by Mitchell.
These transmissions are quite expensive and are not an overdrive, but the revised gear ratios make it much more drivable than the stock gearing.