I seen where some of you use a % factor to checking for max towing weight. I checked my max towing weight for the f-150 and it is 6300 lbs. I don't travel to the west but thee are some mountains around northern Alabama that I sometimes travel to. I would be hauling a 650lb atv with me from time to time. What trailer weight should I look for? I know this question has been asked a thousand times. So any help would be appriciated...