Cadillac Repair: cadillac engine keeps overheating, blown head gasket, head gaskets

Question
I keep having my Cadillac engine overheat, i have changed the radiator, water pump, thermostat and spark plugs as well. i was told that it could be a have blown head gaskets but there appears to be no water in the engine oil or leaks on the engine block that would show a blown head gasket.could i have back pressure in the cooling systems or would i need to take the engine apart to check the head gaskets? looking for any kind of help please..

Answer
This engine is highly prone to small leaks in the head gaskets, Just enough to build up pressure within the coolant system thus stopping the normal flow of coolant due to stretched head bolt threads in the aluminum engine block.

There are numerous factory bulletins referring to this problem and the fix is to drill out ALL the head bolts and install steel heli-coils within the engine block and install new larger bolts.