Makes sense. Without the synchro rings, the transmission could be shorter. Are older transmissions still SM420s? Other than the synchros and shifter, is the rest the same? I still can't get the shifter out of my "real" 420. It's spring loaded in the upwards direction but not downwards. Coming out of a '53, it may be an older one. Also, I read info on how the one casting number is a date code. The letter being a month, then day, then year. Mine is F642 on the 420 which doesn't add up. I know.. just use it and be happy, but part of the fun is the research. Also, I have pieces and parts from a '46 1-ton. Would this truck have an open driveshaft? I need to know which trans to keep for this project. Any help on these topics will be appreciated.
