Sounds like a standard holiday, visiting all the repair shops on the way.
You had more overheat problems after you cleaned the rad?
If you only use garden hose pressure, or less? (my pressure is about 40# here)
and use degreaser and be carefull, you should not bend the fines on the rad. I have had no real problems. (temp ran up on a trip in 2009 in 39*C = 102F on the long East pull out of Osoyoos, BC. 49.009582,-119.411007 - Google Maps
I just geared down to keep the RPM at 2000, shut down the AC, and kept moving.
I have, since that time, installed a two-way vent on each side to assist in air movement over the batteries/exhaust area, and the AC Condensor/engine area.