I would suggest one of the last years of the Ford 7.3 (2003.5) but a low miles one will be at you upper amount. I would get the manual 6 spd (auto tranny weak link) and the turbo can be tricked into beind a surprisingly good exhaust brake for $10. It can also be chipped into putting out a lot more than the stock 275 HP.
The weight police will jump in that you cannot pull your 18K with a 03 F350 but I do it often. If you could find a F450 crew cab 7.3 even the weight police MIGHT back off. Nah they will say you need a MDT.
