This is my son’s F250 with a medium sized load. He has a 4” BDS lift w/ Fox shocks and 37’s on stock 20’s. That is my old truck as I went to an F-350 recently. Since yours is an F-350 you won’t have to worry as much with the squat but with a gooseneck or 5th wheel you won’t have much clearance over the bed. He’s pulled a couple of loads and said it does fine and isn’t squirrelly at all. We are in flat country down here so your driving conditions may be more extreme. Good luck.