The overall diameter is less than 5mm larger than stock, so I'm going to say that the spare wheel well has room for 2.5mm per side for the clearance. I think your issue will be with the width. That 285 tyre is over an inch wider than the stocker and I doubt that the load floor would sit right with it there. It's been awhile since I looked under there so don't take my word for it. Go look at your truck and see if there is 1" of room to give.