The photo OP posted is a 6 bolt wheel
GMC made somewhat rare long box 1/2 tons that were 8ft boxes
The internet is full of instances where people get one and want to cut it shorter (and have)
I’m very curious if this rare 1/2 ton uses the 3/4 ton frame or if it is a definitive long 1/2 ton style frame
Getting underneath it would be the most interesting thing to me.
I have a couple 3/4 tons in my collection one started life with a 3speed and was converted to sm420 on the floor and the other appears to have always been a floor shifter model.
I do not own any 1/2 tons to compare the frames
-s