Ford Repair: Ford Mecury Sable1994/ overheating, blown head gasket, coolant water

Question
How can you tell if you have a cracked head/block. The car overheated about 2 weeks ago and we replaced the thermostat.  The car hasn't given us anymore trouble till yesterday.  It overheated and spewed out the overflow tank.  We are not sure how to tell if there is a cracked head or what to do now.  The car is a 1994 Mercury Sable 3.8 Thankyou.

Answer
Hello and thanks for the question...I'll try to help.
It's most likely NOT a cracked cylinder head. It is most likely a blown head gasket. The 3.8L are notorious for having the head gaskets go bad.
To check it ......fill the radiator with water and then remove all of the spark plugs. Then pressurize the cooling system and note if there is coolant/water pouring out of any of the cylinders. To pressurize the system rent a system pressure tester.
Erik