I have replaced the Gasket twice. The Stat Housing is newer with no Corrosion. It is flat. The Intake Manifold Outlet is flat. I have always used a Gasket and Gasket Maker (Permatex etc) together. Never had a problem. Doing some reading it is not recommended to use a Gasket and Gasket Maker together. Just use a Gasket Adhesive. I cut my Gaskets from a Sheet about 1/8 inch thick. I have one thin Paper One left from a Gasket Set. I would have thought the thicker Material would be better to use? Any Tips anyone wants to offer that You find works?