If it did, they didn't bother to put it on the trucks until '47 when the Advance Design trucks were introduced.
I've got stacks and stacks of info on truck models collected when I was building the VIN Buster, and the first time I saw the 3xxx designation appear in the data was beginning late 1947.
Altho that doesn't mean they didn't use it earlier, I just haven't come across anything indicating they did prior to 1947.. but I have heard individual truck owners use those series numbers to identify their trucks (i.e. saying '42 3100 instead of 1/2 ton)
