FWIW, we bought a '15 F350 SRW cc, 4x4, 6.7,sb in late '14.Off the lot purchase, but really liked the truck and towed/handled our '06 Cedar Creek Silverback (10,800 dry, 13,800 max, pin of 1800) w/ ease. Last year, we upgraded to coach in sig knowing it was over trucks GVW's. Probly get blasted here, but I really wasn't concerned about the truck as Ford (and GM & Ram probly do the same) more than likely tested it w/ a much heavier trailer than what we have. I'm not talking thousands over, but trucks GVW was 11,500 and fully loaded came in at 12,300 w/ 5er and no one in cab. Enter this year and vaykay plans. Looking at going to FL in mid summer and roast our garbanzo beans off. With the '15, I just simply NEVER gave the tires a thought as to how much weight was on them. Looking back thru my scale notes, and weight ratings of tires, discovered we were over on rear tires by few hundred pounds (again w/o humans, just the 5er). Around here in CNY, really not a big deal. HOWEVER, with going to FL in height of summer heat, ambient air temp, road temp and temp of tires just by towing was putting a huge pit into my stomach as to what would happen to tires given the 3 heat factors. My Mom always told me to trust your gut instinct. Sadly, as much as we liked the '15, we upped to a '17 F350 dually, cc,4x4, 6.7. Really didn't want to, but getting a lighter/different RV wasn't going to happen. At least now I know I can rest assured when the wife is driving and if a drive tire lets go, she will be okay getting to side of road.
So moral of this reply is: I feel the OP is good up to 14,000-14,500 max trailer weight. If you foresee absolutely NO out of state or region trips at anytime, you could squeak by w/a 15,500 but ONLY w/a 350/3500 SRW. Beyond that, dually.
