[_Ogre]

me personally thinks that your stock truck performed exceptional in 105* temps
not sure anything you do to it will make it run cooler climbing a grade like that in those temps
a real temp gauge with numbers rather than H---C might give you acurate readings too
even if it's wired temporarily wire tied under the dash

if you did that climb regularily in those temps a wiper washer pump spraying in front of the radiator would drop the temp gauge
my 56 chevy 48 pass schoolbus/camper had a similar problem on long grades in high temps
i carried a couple gallons of water and would use one gallon to cool the motor before shutdown