Ike, try the Colorado Rockies grossing 27,000 pounds in a pasted together 1-ton Cummins conversion.
Long, slow climb with an engine that overheated every 2 miles (bad clutch fan).
No place to pull over (10 foot plow piles), all you can do is nurse it to an opening to cool it down.
I've had several times where a not up to the task fan clutch bit me in "the hills" and I'm of the mind that I'll carry a new one when I start grossing over 20k with even a hint of getting into high altitudes.
Jon, I'm thinking I'll just put an old 1982 Dodge 1 ton Dually Crew I have here back together, with a 3.07 axle, my donor engine and a Getrag.
I'm not going to continue chasing the impossible dream of rustfree Chevy junk, when I know DODGE inside out, upside down and backwards.
SPEAKING of cool places to visit, try the backroads heading (due) east out of Taos, New Mexico, over towards I-25.
Red rock, sheer faced mountains, with pine trees and a somewhat sharply winding road.
In January of '09 I started out near Taos, in 1-1/2 feet of snow and still coming down, halfway through to I-25, it was bone dry and sunshiny.
2 major seasons in the space of 100 miles!
Nature's beauty at it's finest!
Mark.