The trailer should have its own brakes, right?

Does it have a load leveler hitch?

I have towed a Toyota Landcruiser fj40 with my D100 with drum brakes over the mountains. Brakes were never an issue. Spending 5 1/2 miles uphill in Second gear was a bummer, but I made it. Last tow was in a '95 or so F150 with the trailer tow package, we used the stock bumper rated at 5000lb and towed my D100 through Flagstaff.

Seems like you're going to do it. My advice to you is "low and slow". At some speed your truck is going to feel like the trailer is steering it. That'd be your maximum speed. Leave plenty of room ahead of you, keep to the right lane as much as possible.

I'd agree, don't use overdrive. At the speeds you'll be going you won't need it.

I'm sure your 4.7 has as much or more power than my 318, and that's not part of the difficulty anyway. You could do it with a Slant 6. Just take you longer to accelerate.

If you were going to do this weekly my advice would be different. I'd say get a stouter truck. But for once in a while towing relatively short distances it'll work. And the extra fuel won't be nearly as expensive as renting a 3/4 ton truck for a few days.

R.