What gear ratio is used when the towing package is factory installed? I'm thinking they lower the gearing a bit. I have a Sport package 4x4 without the tow package and need to tow. I can add the hitch, electric wiring and transmission cooler, but was wondering about the rear. The build sheet says I have a 3.55 rear axle ratio, but then it also says I have a Corporate 8.25 rear axle. If the truck had the tow package, what would be different?