I'm towing a 30' 8000lb loaded travel trailer with my 2001 V10 Excursion with 3.73 gears. It's one of the best I have used so far, and I have towed with the following vehicles, 2008 F250 6.4 Diesel, 2008 Chevy 2500HD 6.0 Gas.
I did add a Hellwig rear sway bar, new KYB Monomax shocks all around, Air Bags, 5-star tune, and some other goodies cause I wanted em. The best handling for towing was the rear sway bar.
Just let the V10 rev up and it will tow that unit without much issue. I tow larger hills around 55-60mph which is within posted limits, no complaints!
2009 Ford F350 V10 4.10 FX4 Crew Cab SRW, Timbrens, Leer Topper