I have a 2001 Ford Expedition 5.4L 4wd w/3.31 gears (9.75 rear/8.8 front), and stock P255/70-16 tires. Gross towing weight at stock configuration is 6300. After market additions are the hitch receiver and Hayden tansmission cooler.

This year we bought a hybrid travel trailer, which grosses at 4750. Before that we had a popup that weighed significanlty less.

On the flat land the truck felt slightly more sluggish than w/the popup. But, when we hit some hills going to the Shenandoah National Park in October, it was pathetic.

I've considered the cost of a diesel F250/350 w/a diesel, but they are too much, especially w/any hit that I would take on the Expedition. So, I ordered, and I hope I am on the track here, 4.10 gears w/master installation kits from Reider Racing. I am also going to upgrade my tires to a LT265/75-16 (D tow rating).

Has anyone done a similar change on a similiar vehicle (Expedition/Navigator/F-150, etc)? Has anyone that is knoweledgable on this topic seen this change? If so, am I on the right track?

I don't see an upgrade in the camper at all for at least few years, so this RV setup will have to last us a while. And, I don't see being able to move to a different truck until the better half's car is paid for. What I am really looking for is some reinforcement (and/or constructive criticism) that I am on the right track here in my thinking.