I just drove across the country in my 85 westy with no problems. Driving
from Phoenix to Flagstaff in  a snowstorm my bus started running cold.
Really cold. In Flagstaff the next day it still ran cold and a signifigant
drop in power. When I drive around town awhile the temp comes up but it
still can't get out of its own way. I just had the head-gasket done. It
also idles rough when cold and stalls when it first starts. It idles
poorly when warm too. Could the altitude from Phoenix (1000 feet) to
Flagstaff (7000 feet) cause the problem? Thanks!

-Mike