95 inch engines. 9.8 to 10.2 CR. Maximum torque and horsepower at mid and higher RPM ranges. Use high-lift springs. 2600-6200 RPM. These cams are used to convert a 99-06 Twin Cam from the stock ''silent chain drive''; which is equipped with spring adjusters; to the ''roller chain drive'' with hydraulic adjusters that work on engine oil pressure. This roller chain and hydraulic chain adjusting system; which is much better than the early system; is used in all 06-17 Dyna and 07-17 Softail and 07-16 Touring models. Note: Cams are for use with splined (00-up style) driven gear. For 1999 Twin Cams splined 503575 driven gear must be purchased separately. Note: See our catalog for additional required parts.