Kibblewhite Ampco-45 Exhaust Valve Guide For Harley Features: Precision-machined from Ampco-45 Compatible with no-lead fuel and accept any type of valve-stem material Provide maximum service with chromed valve stems Feature a tapered nose design for maximum bearing service and minimal port obstruction Improves flow characteristics Accept .600 lift cams also accept OE top hat valve seals (sold separately) Accept OEM lower collar Guide OD .5620 Guide ID .2750