Truck is 1/2ton . I have checked with oldgmctrucks .com, but they were not much help. Casting # and SN: all stated with 1938. Can not find much with Chassis # of 15628. This is the # on the data plate mounted on the firewall inside the cab. Also model is -- 7 -- 14 -- B. Am sure it is a 1937 , Is this 7 for 37? What is the 14? & B? Also Straight Rating # 4600.