Over advancing cam timing is unlikely to cause overheating. Running too retarded is what most likely will, as combustion is still occuring late and while the exhaust valve opening, thus thermally overloading the exhaust water jacket.
Over advancing will either cause knock- where the engine is knock limited- or you wont be getting best torque/fuel economy- but shouldnt run hot. If anything- over advancing may run a tad cooler.
I have an overheatng problem with my Chally on long distance high way trips- where the temp car climb as high as 260 deg F!
Ive ordered a specially fabricated aluminium Be Cool Radiator, as I didnt think it could be the fan (runs fine in trafffic/low speed) and the thermostat is definately opening- as I can feel that the radiator is warm and being utilised!
Good luck
