I need to replace the tires on my 2008 Ford F-250 SRW 4WD. I use it to pull a 2-horse gooseneck, all aluminum. The tires that came on the truck when I bought it used were LT285/70R17E, however, Ford recommends LT265/70R17E. Seeking advice on why the larger tire might have been used and whether I should stay with the 285 or go with 265.