is it necessary to have the head machined to remove all pits or will the gasket seal against these imperfections?
The cylinder head gasket mating surface must be machined flat to ensure a proper seal and the exhaust manifold mounting surface may be machined if there is an exhaust leak there from the cylinder head warping. A few small pits across the surface may not affect sealing that much if you use the right gasket and some sealer. Consider hring an experienced technician like one from YourMechanic who can come out an take a closer look at the exhaust ports on the cylinder head to offer a more personal diagnosis.
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