K3500 towing specs

[SkyePN]

Hi new member probably have lots of questions as I fix up this truck.

Picked up a 1988 K3500 with the 6.2L diesel recently, the stickers say:

GVWR 8600 lbs
GAWR front 4250 rear 6000
Cargo weight rating 2756 lbs

So I assume the truck weighs about 8600 - 2756 = 5844 lbs?

If I install a 5th wheel hitch the tongue weight would be considered bed/cargo weight?

Can't find a GCWR number anywhere, how much can I pull?

Thanks