Valves, Select Fitting

If the valve stem-to-valve guide clearance exceeds the service clearance, replace the valve guide and /or valve. Always reface the valve seat after the valve guide and /or valve has been replaced.
In the case of valve stem-to-valve guide clearance, the service clearance is intended as an aid to diagnose engine noise only and does not constitute a failure or indicate need for service. However, when overhauling or reconditioning a cylinder head, the service clearance should be regarded as having a practical working value and used as an aid when installing the valve guide and/or valve to ensure extended service life.