I'm guessing its a 48-50 by the grill opening. I just noticed you model #, a B-2-B indicates: The 1st "B" is the truck series, B. The "2" indicates the 2nd change in the series, 1950. The 2nd "B" indicates it is a 1/2 ton 108" wheel base.

The trucks also have an engineering code. The letter prefix and the three digits made up the first part of the truck's engine number.
B-1 1948-1949 engine numbers T142xxx is a 1/2 ton, T144xxx is a 3/4 ton, and a T146xxx is a 1 ton. A T136xxx is a power wagon engine code (the book also shows a T137xxx as the only engine code for the power wagon, guess its your choice?) and did not change during its entire existence.

B-2; 1950 T172 is a 1/2 ton, T174 is a 3/4 ton, and a T176 is a one ton.

B-3 51-52 T306 is a 1/2 ton, T308 is a 3/4 ton and a T310 is a 1 ton.

B-4 1953 engine numbers are the same as a B-3.

The book source is odge Pickups History and restoration guide 1918-1971 by Don Bunn & Tom Brownell copy-write 1991. It has proven to be pretty accurate through the years. Gene