I have had a 901 transaxle (that came as part of a '60's sportsracer basketcase project I purchased) kicking around my garage for several years, and have finally decided to try to identify it. The maincase casting date is 33/65, the serial # is 222871, the tailcone casting # ends in OR, which means it's probably not original. The issue is that there are no other numbers stamped on the rib, and the rib is still in original condition, leading me to believe that it never had ID numbers stamped there.
The transaxle was suposedly pulled from a low mileage car in the 60's and stored all this time. Does anybody have any ideas?

 

The type number, if it is still present, is farther along the body of the case, adjacent to the ring and pinion side cover on the same rib where you found the serial number.

That tailcone is probably original. The serial number matches the Pro Date you've published. Other cars with similar serial numbers on their gearboxes were produced in Sept and Oct of 1965.

Regards,

Matt