Cadillac Repair: Head Gaskets, head gasket leak, head gasket sealant

Question
How much would replacing the head gaskets on a 92 deville, and how  mkuch would be considered too much. And do head gaskets sealant work

Answer
Head gasket sealant is only good for clogging up your heater core. Your problem is more likely to be that the aluminum threads in the engine block are stretched out thus allowing the metal head bolts to loosen and cause the head gasket leak.

You need to drill out all the engine head bolt holes and install metal heli-coils in each hole and replace all the head bolts.

This is very very common with this engine.