Kibblewhite Manganese Bronze Valve Guide For Harley Panhead Shovelhead Features All Kibblewhite Guide profiles are designed to have a minimal effect on the airstream while maintaining critical cross sectional thickness in high-temperature areas, which promotes high-performance and endurance Precision-machined guides Guides can be easily reamed with a battery-operated or electric drill and finished with a high-quality ball hone Eliminates the need for expensive honing equipment that would be required for nickel bronze valve guides Machined to accept OEM and aftermarket seals + .004 Over stock size