Flatness

When a cylinder head is removed because of gasket leaks, check the flatness of the head gasket surface to make sure it conforms to specification using Straight Edge 303-D039 (D83L-4201-A) or equivalent and Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent.

Replace the cylinder head if it is cracked. Do not plane or grind the head gasket surface. Remove all burrs or scratches with an oil stone.