Feuling Valve Keepers For Harley EVO / Twin Cam / Sportster Features Valve spring kits are direct replacement no machining or rocker box clearance required Larger lift camshafts require valve guide machining for seal and retainer clearance .050 offset 10, 5/16 steel valve locks, raises the valve spring retainer to gain .050 installed high without machining the cylinder head spring seat Up to .574 lift for 1984-2004 Big Twin, 1986-2003 Sportster and up to .700 lift for 2005-17 Twin cam