When using screw-in studs on a factory cylinder head it is necessary to machine down the stud boss equal to the thickness of the new stud's jam nut plus the guide plate thickness. The Stud Boss Cutter from COMP Cams comes with a universal arbor that also acts as a pilot/guide and fits into the original stud hole.
COMP Cams Stud Boss Cutter
For use when installing screw-in studs on factory heads; Universal arbor included
