That is a nice looking truck.
I'm sure you know, but it's hard to believe it is only a 4000 model. It has the wide fenders, spoke wheels and looks like a heavy axel under there. I would have figured that it would have been at least a 5000. I'm curious to what size engine you have in there and what the GVW would be. I used to drive a '62 GMC with spoke wheels, heavy specs and a 478 under the hood and it was a 6500 model.
Looks good as a Flatbed.
Bill