I use the flat side of a bench grinder wheel with the paper label removed. Spray the block surface with carb cleaner, and rub back and forth with the grinder wheel. It removes all the old gasket material down to the metal, while maintaining flatness. Be sure to thoroughly clean out the head bolt holes with a tap, then carb spray, then compressed air. Many head gasket failures are due to oil or antifreeze remaining in the bottom of the bolt holes, causing the head bolts to hydro-lock and not getting tight, even with correct torque wrench reading.

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