Valve Guide: Service and Repair

Valve guides are cast integral with the cylinder head. Valves with oversize stems are available in .001 inch, .003 inch and .005 inch larger than standard. Oversize reamers are required to enlarge valve guide holes to fit the oversize stems. Best results when installing .005 inch oversize valve stem use a .003 inch oversize reamer first and then ream to .005 inch oversize. Always reface the valve and valve seat after reaming valve guide. Valves are marked .001, .003 or .005 with colored ink.