Thanks for your reply 3B, it really helps a lot. I guess I was thinking that 41-46 came with 11" or 14" brakes. But this truck has obviously had some changes to it, so helping me identify what I'm trying to work on is greatly appreciated.
So far, I'm fairly comfortable in saying the truck has a 41-46 3/4 ton frame, with some modifications we're discussing here. It has a '41 cab and front clip.
I was searching different year trucks on Rockauto and did see some brake shoes for close to 12", so I'll figure out what year and model will work.
Here are some pics of the rear differential:
41 rear diff 2 Click on the right arrow to see the front.
The only numbers I could find on it are located on the left front side:
3698535
Thanks again for your help.