A method of manufacturing an engine block is disclosed. In one embodiment, the method includes providing an engine block including a cylinder bore and a top deck with a head face including a predetermined surface roughness. The method also includes masking the cylinder bore with a masking plug, the masking plug being located at a predetermined insertion distance measured from a masking plug outer surface to the head face. The method further includes applying a corrosion resistant coating to the top deck over the head face and machine finishing the engine block including the coating to the engine block specifications.