cooling system wouldn't stop an engine starting so need to check the fuelling system and compression first, worth checking why the car was overheating too or it will happen again, check thermostat, fan switches, clogged radiator. check the head gasket first as this will most likely cost the most to fix, when the engine is cold remove the oil cap and look for a brown milky goo on the bottom of the cap. check the plugs for any rust or water fouling, start the engine with the plugs put back in and whilst its cold remove the rad cap and check for bubbles whilst the engine is running, get a compression test from a garage, all ways the check your gasket, doubt the block would of cracked. hope you manage to get it fixed.