Hello Bluto. K10, I must respectfully disagree, as my 1963 Service manual covers the repair specs for the 'new 12bolt axle' that debuted in 1963. The 1/2 ton axle from 1960-62 is the same animal as the earlier 50's 1/2 ton trucks, other than open driveline.
Anyway, Bluto, a few years ago, I bought the complete rear end from a 1964 1/2 from a guy in Stallings, NC. This rear axle was factory posi-traction. Unfortunately, the differential ended up being too wasted to rebuild, so I ended up rebuilding the stock axle from my 1966. The point of all this is, that I still have the stock 1964 17-spline axleshafts from that 1964 axle. You are more than welcome to them, just pay shipping. Or, if you are going to the Charlotte AutoFair in April, I can meet you there.
If you want, send me a reply to this e-mail address and I will send you pictures of the axleshafts. They are used, but don't have grooves worn in the bearing surfaces.
[email protected]Seth K. Pyle