i dont compete or anything but i wouldnt be afraid to.. i think my dads 7.3 f350 would be pretty good at it. 8,500lbs with around 700lbft of torque. 4x4 with big tires.
just remember that sled pulling is hell on trannys, transfercases, everything behind the engine.
and the bigger and heavier with the most aggressive tires usually will out pull the others.