Machine valve spring seats for proper installed spring height and spring cup fitment. Cutter bodies and pilots are interchangeable, Hardened pilots fit all 3/8 and ½ hand drills. Cutter: Cuts Spring Seat .625 ID x 1.750 - 1.755 OD Cutter uses the following Pilots: 707265 Fits valve guides with 3/8" ( 9.53mm) valve stem, 48-83 Pan & Shovel 707263 Fits valve guides with 5/16" (7.9375mm) valve stem, 84-99 Evo; 99-04Twin Cam and 86-22 Evo XL 707264 Fits valve guides with 7mm valve stem, 05-17 Twin Cam 707262 Fits valve guides with 6mm valve stem, 17-up M8 707266 Fits valve guides with 11/32" (7.7313mm) valve stem Note: Special Order Product only. To order please contact your MCS sales representative.