I have an 85 765 turbo...various mods, electric fan, and a 3 row radiator was one...I had a problem where it would run hot, only in semi-warm to hot weather, only with the a/c on, at highway speed (60-mph) only going up a grade, or just under steady low boost. In traffic it was fine, but would occasionally and randomly start to run hot, then come down immeadatly after turning off the a/c. New headgasket, 82 degree thermostat, lower temp aux fan switch. Everything was new. Problem was solved with a sugestion from a fellow brick board member. After washing it the other week, I decieded to pressure wash all the crap out of the a/c condensor, intercooler, and the radiator. I took out the intercooler, and washed that down, got behind the condensor and hosed that down, and the radiator was pretty new, so i just hosed that off. It didnt look like too much came out, except a lot of dust from the intercooler. But now the guage will just hit the half mark under boost, going up a grade, with the a/c on. WOOHOO!! problem solved..I hope this may help someone in the future. Thanks