I had the same truck/engine/year sans the 4x4 stuff. Great truck, not a single problem ever, good mpg. All I ever towed was a couple of Sea-Doos, but IMO, the 5.3 with that gearing will make STEEP hills slow-going. That engine needs to revved up a bit - you'll want to be sure to use the Tow/Haul switch. OTOH, what you eastern fellers call "mountains" we call "hills" out West.
My Dad has had quite a few different trucks and trailers. He always bought the truck first then would buy a trailer approaching its towing capacity, decide the truck wasn't strong enough, buy a bigger truck, then buy a bigger trailer, decide the truck wasn't strong enough, buy a bigger truck, then buy a bigger trailer, etc....
