So confused about towing

2Macs wrote:
You did not indicate whether your Dodge was gas or diesel. If it is gas, then I agree with the dealer. If diesel, what size diesel? You must remember, the major requirement for towing is not horsepower, it is torque. Torgue determines the ability to tow a trailer, either TT or 5th Wheel, especially in the hills and mountains. Gas engines do not have the torque required to tow a heavier 5th Wheel. Check the torque of your Dodge. If it does not have at least 600 ft lbs of torque, forget it or purchase a new tow vehicle.

I think you're more confused about towing than the OP.
What do you think people did before the New Millennium?
I personally ran over mountain passes with 22,000 pounds total truck & trailer with a 1986 GMC crewcab dually with a gas 454 for many years. It was the strongest truck you could buy in its day.
I always got there and in fact I never sold it and keep it sitting out back as a "plan B" because it ALWAYS gets where it's going. I also had numerous gas Fords back in the day that worked just as hard. None of them had 600 ft/lbs, not even 500.

These new extremely torquey diesels will go faster up the hills, but to suggest that anything without 600 ft/lbs won't get the job done is simply not true.
Way WAY back when, I drove an F600 tow truck with a gas 300 six-cylinder. We called it "The Creeper". It wasn't fast but it got where it was going, loaded way heavier than these pickups with RV trailers.

Second major disagreement: my Cummins came originally with 420 ft/lbs torque. It would tow any 5th wheel up any mountain. But you don't have to "purchase a new tow vehicle" if you want more. I will challenge you to keep up with my old Dodge up any mountain pass, and I'll bet the title of the truck you'll lose if your truck, any brand or model year, is stock. You'll lose. Badly. And yours will break sooner too.
If you want more torque, all you need is to know how it's made and what to do to get it.
You don't have to buy a whole new truck.