FWIW, My Canadian 1940 GMC is a 1 ton model 9400. I don't believe a 1 ton was offered in the US that year. From what I can tell, my 1 ton is basically a 3/4 ton with heavier rear springs and larger rear brakes and 17" wheels.
Anyway, I'm pretty sure that the rear fenders on my 1 ton are the same as 1/2 and 3/4 ton.
Steve
