GMC made their first 1/2 ton truck in 1936, model T-14. It had a 126 inch wheelbase and was powered by an Oldsmobile 213 engine.
For 1937 the T-14 came in two wheelbases, A was 112 inches and B was 126 inches. It was powered by an Oldsmobile 230 engine.
The ID tag on the interior firewall was the "VIN" tag for your truck. The same ID number was stamped on the frame on the passenger side just forward of the axle. There is also an engine number stamped at the top front side of the block on the drivers side near the water pump. The original ID number on the title may use one or the other of these numbers. There were 23274 T-14's produced in 1937.