Is changing my gears the answer?

[late_chief]

Today was the first day I towed my 6x12 enclosed trailer to the mototrack. As excited as I was, it was a bit of a drag. My truck had a heck of a time going 60 on the freeway with just the trailer behind me... Not to mention the second I hit the tiniest incline the truck downshifted and couldn't barely keep 55 up. I have an 03' F350 with a 6" lift running 37's. My gearing is a 3.73. The truck just drags and can't pull. Is stepping my gears up to a 4:10 ratio the answer? I want to keep my 37's on so what would be the answer? I'm not that interested in going crazy with engine mods, my intake and exhaust is about as much as I want to do; but I'm open to suggestions. thanks for your input in advance~

[late_chief]

Since posting my question I have done a lot of reading and plan to contact a local ring and pinion shop tomorrow. It looks like gears are the answer. Thanks for looking, I'll do more reading next time BEFORE i post a quesiton

[Greasy_Dually]

On that subject, try and get your RPM at 55 around 1800-1900 which puts you at 70 at around 2200-2300, then you'll be right in the torque band and probably won't down shift much. But if you do downshift at 55 your rpm in third would be around 2500-2600 which should be sustainable through out the climb. That would seem like a minimum, you may even want to go lower.

[late_chief]

Thanks, I'll continue to look more into it-

[amunderdog]

Did not give full specs on truck. Turbo? Aod trans? 10.25 diffs? I will guess 4X4.
Anyway JawsGear.com has a good calculator.
If you are going to pull with this truck.
I would consider 4.56 ring and pinion swap.
Top speed would be around 70 to 75 Mph.

[Hunter62]

amunderdog, nice gear/RPM calculator!

According to his sig he's got an '03 6.0 4x4 which means it's got a TorqShift.

I've got 35's on mine and want to change out the 3.73's for 4.30's, that should be perfect for pulling my trailer.