[63burban4x4]

It seems to me that the size of this truck is unusual....heavier than a C-30 but lighter than a C-50 or C-60? I don't really recall a C-40 size, was this 4000 GMC rare?
It's interesting that the truck seems to have the lower, lighter cab (no running board step) but has the flared big truck fenders. I can't tell if it has a large grille shell, like say a C-60 would have...........the bigger trucks were taller in the front sheetmetal somehow, maybe a raised radiator support. I wonder if the company who did the conversion could have changed out the fenders? (I'd say it's pretty likely that a truck like this went straight from the factory to a driveline vendor then to a dealer,or even straight to a fleet) Do you suppose they shipped out of the factory without any axles at all?