How about the GM military trucks from the late 40's, certainly narrow axles and appropriate size or weight capacity compared to later military stuff.
How easy would an AD cab replace the 40's cab?
Or again just use whichever truck as it is.

•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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