[ecomodded]

There must be a cheaper alternative to the Evans coolant, I don't know what it is, There is a lot of fluids out their, must be a way to do it on the cheap. Great idea though, having a higher boiling point coolant.
WD40 , If you punch a small hole in the current rad cap, it will become a 0 pressure cap. So can modify and use the same cap.
Might be possible(most thing are) to manipulate the thermostat to open at a higher temp, possible by heating the spring to weaken its tension, could try it on a few thermostats to see how little or much heat is needed. Heat may completely ruin the spring also, its a theory..