I changed my vote based on the recent addition of pics. This is a straight forward longbed 3/4 ton. There is not a cutout in the rear fender for the spare. That spare tire is huge and takes up more real estate than a stock tire would, causing the optical illusion of a shorter bed in the original pic presented initially, which was taken on a 45 degree angle.
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission