Most likely your truck was not designated Thriftmaster or Loadmaster, since it has a late 1949 engine, you most likely have a late 1949 truck (if that is the original engine).
Do you have hood side emblems?
Does it look like this? (1947 through mid-year 1949)
or
Does it look like this? (mid-year 1949-1952)
There were two emblems on each side of the 49-2nd through 1952 hoods - the emblem above and a model number emblem just below.
Chevs of the 40s has a variety of hood side emblem photos. 
