I had a 94 f250 w/351 and a 5 speed. It had 4.10 gears and 33x12.50 wild country's. I pulled our aluminum gooseneck(20,22? ft. w/2-7000 lb axles) and averaged approx 10,000 lbs of hogs (that was the weight on the ticket-what the hogs weighed after I unloaded them). It worked the truck, but it handled it ok. Be sure you have a brake controller, I didn't the first 3 loads, and it was alot of weight for the truck brakes.

Anyway, just thought I'd mention this.