The stock shoes on a 1946 3/4 ton are as follows:
1.75" x 11" on the front drums
2" x 12" on the rear drums
I'm not sure what the drum sizes are, beyond the fact that the front drums are smaller than the rears.
The Body Serial Number is located on the cowl on the passenger's side. It should look something like this: 21DR-C3490 (that is mine).
The number at the beginning is the plant where assembly occured, the two letter code (DR) tells you what size truck you have, the single letter code (C) is the month of manufacture, and the number is the serial number, starting at 1001.
