Re: Towing a 5000pound trailer with a E350 5.4/3.73
It's ~$800/per axle, depending on labor rates in your area.
3.73 to 4.10 will hardly be noticeable. If you decide to drop that kind of cash, go to a ratio that will actually make a difference like 4.30 or 4.56. I have 4.56 gears with 265 tires.