Short answer is no, the 1973 C60 wheels won't fit the AD 1.5 ton truck, different bolt pattern. Measure them and compare.

For more detailed info check out this Tech Tip
http://www.stovebolt.com/techtips/wheels/
Likely you can use 19.5 wheels from a step van or Chevy 3500HD, but check to see they fit over your brakes first. If they fit you'll still need bushings made to adapt the small hub to the larger wheel center hole.
Or a better looking solution is 22.5 wheels, but a little harder to find, read all about them in the tech tip.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-