I love your truck!
I'm not sure I understand your question about the rear tires. You should be able to unbolt the outer dual and remove both. A Chevy 1-ton with duals would have 18 inch wheels and take a tire that seems to only be available from limited sources. I can't tell from you pictures what tires you have, but I can tell the wheels are different than a 1-ton Chevy and different from what is found on GMC trucks just a few years later.
You call it a '46 but say its titled as a '47. Poke the serial number from the body into the serial number tool at
Maxwell Garage. That may clarify if it was made in '46 or '47.
