1994 Pontiac Sunbird car overheated

either head gasket or the cylinder head itself is cracked and needs replaced

aluminum head engines will tolerate moderate overheating, but i'd say no hotter then 230 to be safe. its not so much a headgasket problem, but the head itself usually cracks. spilling antifreeze into the cylinder. antifreeze does not burn, which means your spark plug will foul. worse, water, or antifreeze does not compress like air, and causes extra pressure in the cylinder. this pressure in turn goes through the cooling system, and usually causes radiators/puke tanks to over flow. but, if you dont mind it running like crap, or any of that.. the damage is already done. it wont hurt it any further to run it. it will always miss, and blow smoke and coolant out though.