Timing can cause the engine to run hot, but 215 or more is probably caused by something more serious. Try checking for a leaky head gasket or cracked head by removing the fan belt and the thermostat housing. Fill the cold engine with coolant up to the level of the the thermostat, start it, and goose the throttle a few times. If bubbles come up in the coolant, they are coming from a compression leak, either the head gasket or a cracked head, etc. The engine will run for 2 or 3 minutes before the coolant around the cylinder walls starts to boil due to lack of circulation.
If you don't find a compression leak, look for late ignition timing and/or a water pump impeller that's slipping on the shaft. Just because the pump shaft and fan are turning doesn't mean the coolant is circulating.
Jerry
