Hank,
Here is a screen shot of the original 1946 wheel specs from the GM Heritage site
1946 Truck Data.
I know this doesn't fully answer what will fit, just what was there originally.
I am sure others will jump in here soon and try and add some more info or replies to help answer your question.
When you do figure out for sure what you want to find/buy, be sure to post an ad in the
Truck Parts Wanted forum .
Dan