Well I just joined due to the fact that my mother own's a 1990 Mercury Sable 3.8. Well her headgaskets are bad and leaking oil into the exhaust manifold and constantly is smoking. Well I not familiar with this OHV models (more familiar with SOCH and DOCH models)and I'm here hoping somebody is well informed and help me with guidance so I can replace it.

 

are you sure it's the head gaskets (those should be below the exhaust manifolds) and not the valve cover gaskets (above the exhaust manifolds)?