I was wondering if the retainer (I've been calling it a cover) (4.317 on the diagram) the same or different between the 1/2 and 3/4 tons? Also, see Tony292's first post for picture of retainer. Thanks.
I think they are the same, but I'm not a 100% for sure.
You should call these guys
http://nwtparts.com/ ask for John,
He knows a lot about these old transmission.
In the meantime here is a 1950 3/4 ton SM420 rebuild
https://pbase.com/dennygraham/sm420_rebuild&page=all1950 3/4 ton enclosed front driveline rebuild.
https://pbase.com/dennygraham/driveline&page=allBecause you're trying to mate this up to a 47 torque tube its a little tricky because its a one off year.
John will set you straight on what you have to do.
You need to find out your torque tube length and ID the transmission & rear axle.
Carrier Assembly: 1947, 1/2 ton, 62 1/2" long (Torque tube)
Source, Grp # 5.504xfiles