I would say that if the head gasket isnt leaking now it has either been replaced or is ok and will be for a long time still. I wouldn't worry about it. These engines are generally reliable. Some, but not all that many, have spark plugs that have blown out. I've seen a few with broken exhaust manifold studs causing an exhaust leak. Off the top of my head I can't think of any other real chronic problems. Of course it's late and I'm sleepy though so I migth think of other things later