Excess heat is more likely to come from too little advance than too much. If you have too much advance, it is more likely that it will ping so badly that you wouldn't want to drive it or that it would fight the starter bad enough to make starting difficult before it ever overheated. In what vehicle is the 350? If it is in a truck in which a V8 was an option, the answer to your cooling problem could be different than if it was in a AD, for instance. Actually, you may not have a problem if it doesn't go much above 200, but it would be better to have the cooling system able to keep it near the thermostat setting.
