First of all, does this truck have an opening and closing vent on the driver's side just in front of the door? Secondly, does this truck have full glass windows in the doors without vent glass, or is the frame for the vent glass there but the glass isn't? If the windows are all one piece, and the vent is there, your truck would be a late '40's model. The vent proves your truck is from the years before 1950, but the windows can be up to 1951. Also, is the box long, short, or is it a stake bed? Finally, is it a chevy or a GMC? That part matters for identification because the model numbers are different for Chevy's and GMC's.