I've been having a problem with a leaky head gasket.Tried the fiber Cometic it leaked from the combustion chamber to the water jacket.I have a stock metal gasket on now and its leaking externally from the water jacket to the outside the cylinder.I put on the metal gasket dry.Should i be applying anything to the gasket before installation?I possibly over-tightened the head nuts from an inaccurate torque wrench.Would this over torqueing cause the leak,even if only slight?