1949 and later came with with a tank located inside the cab. The larger trucks had about a gallon or so more capacity, but the tank inside the cab on 1949 to 53 are interchangeable from 1/2 to 2 ton. 1954 is the same dimension, but uses top draw instead of bottom draw. I personally believe that the 1954 and up top draw tank was the safest tank that GM built. Side mount tank were assumed to be protected by the overhang of the body of the truck on larger trucks. The regulations of side mounted tanks are pretty stringent. And they apply to the year of manufacture of the tank, not the year of manufacture of the vehicle.
