Re: Possibly one of the rarer 1960-62 GMC K1000 original parts?
 

It may be an aftermarket Chevy/GMC accessory. Who knows. I don't get the feeling it is a piece off of a 100T GM factory stamping die. It has the look of a good sheet metal HVAC type guy. I think it was "sold" to owners, not that it had a need....nor designed by GM engineers. Good conversation piece as we have proven.

Re: Possibly one of the rarer 1960-62 GMC K1000 original parts?
 

In the thread I linked on page 1, the truck owners that had them were from California and Utah. Possibly the belly pans didn't survive in the rust belt, which would explain the lack of information or sightings of them.

My truck spent its early years mostly in Wyoming, and was likely stored inside except a couple of months in the summer. That could be why my truck still has a belly pan and it isn't rusted away or tossed when it was falling apart.

Also it appears whoever maintained my truck before I got it did no modifications as my truck was nearly completely as delivered when I bought it in 1978.

Re: Possibly one of the rarer 1960-62 GMC K1000 original parts?
 

Pondering the purpose of the belly pan, I think it is keep debris from coming into the engine bay mainly when off road. The path it is protecting is between the frame rails and mostly in front of the front tires, so it isn't to deflect debris thrown off the front wheels. I think it is mainly protecting from tall grass, brush, small trees or sticks or possibly if driving over crops.

If you drove over plants taller than the bumper, the bumper would knock them down but they would stand back up behind the radiator. This would put them in the area of the crank pulley and possibly the fan. It make also give some protection to the brake line crossing over on top of the tubular cross member on the K1000. The pan also protects the radiator from plants when in reverse.