I would keep it under 4000 LBs on something that old. The newer models with the SOHC can tow more, and the V8 4x2 can pull the most. I have the V8 AWD and the most it can pull (according to the book) is 6800 LBs. So far my loads have been close to that weight, around 5800 Lbs, and it handled it well, it is just a bear to stop quickly, even with trailer brakes and Ceramic pads on all 4 wheels.