Pages 126-131 of this Chevrolet 1953 truck specifications guide give most if not all the answers:
https://www.gmheritagecenter.com/doc...olet-Truck.pdf
Looks like that's where your numbers came from, though. They match I believe.
1954 and 55 first series would be a little different than the earlier AD's on the light duty dimensions because of the rear of the frame being different