That's not empty weight, that's gross vehicle weight rated. Thats empty weight+ however many passenger its rated for, I think they considered standard passenger weight as 150 lbs, then they add on the rated cargo capacity of the truck, 1000 lbs for the J10, I think, add those together and you get GVWR.
And yes I know all of us has probably put a lot more than 1/2 ton in a J10.
82 J10 swb, 360,Offy dual port, edelbrock 600, DUI,3.5in. exhaust, T15, D20 twin-stick, Dana 44 fr, Ford 9in.3.70 rear, 31in. BFG