not much...on my 1995, it could only handle about 800 lbs, then it would start hitting the overloads. i did have broken leafs, but i think max payload is like ~900 lbs or so.
which is too much. actualy payload, 900-1000 lbs. you want to try more, go ahead. im not sure how much new axles, leaf packs, driveshafts, and unbending the frame costs tho...
lol. might want to call the dealer, and have them check it. maybe a misprint? ZR2's arent good for hauling things at all. my 1994 regular 4x4 could haul about 1300 lbs of firewood, only hitting the overloads when i hit a hard bump.