Hi Gun,
I live at 5,500'.� I have gone to the last couple Fall Color Tours where we reach elevations as high as 13,000'.� I've not done anything special when preparing for those extreme elevations.� I am lucky enough to have a high altitude metering rod.� I'm not sure if it alone does anything to help my performance.
At the high elevation, I notice a small drop in power, but that's about it.� Fuel economy also drops a bit, as there is less air.
In prep, just have fresh fluids.� Go through all your nuts and bolts to make sure everything is tight.� The Rocky trails can shake things lose.� Double check your lugs.� � A member of our group lost a wheel last year.
I know you'll carry the basic tools and safety equipment, but you may also want to consider carrying some repair parts.�
Fuel line, wire, ignition parts, duct tape, extra oil and coolant, etc.�
I don't know if it was coincidence, but as a group, (two dozen willys) we lost three or four fuel pumps last year.� We also lost a radiator hose.� One willys also lost it's charging system.� There were other minor issues too, but I can't remember all of them.� Frankly, it was a rough year in terms of Willys failures.
Tim