Valve Guide: Service and Repair

Check valve stem to valve guide clearance. Clearance should be .005 inch
or less. Service valves are available in standard size (.343 inch) or oversizes of .003 and .006 inch. If clearance is excessive, ream valve guide to accommodate next oversize valve. Some engines are factory fitted with .003 inch oversize valve guides and valves and are identified by a "3" stamped on the cylinder head gasket surface in-line with the oversize valve.