I am about to buy a new F-150 4X4 with either the 5.0L V-8 or the 3.5L Ecoboost V-6. Just estimating, I would say that I pull a trailer 10% of the time. Towing includes a midsized boat, midsize RV, utility trailer with a couple of 4'wheelers, small bumper hitch horse trailer, etc. What do you recommend I get for rear axle ratio? THANKS