My guess is that they probably aren't NOS, just salvaged from military trucks. You can bid online for them. The 1 ton axles are more than likely 4.56 and the 10 bolt axles are 3.08 gears.

http://www.govliquidation.com/auction/view?auctionId=7090590&convertTo=USD


1954 3600 Chevy Truck
"The Fake Truck"
In the Stovebolt Gallery
More pix on Photobucket