.518" intake valve lift; .521" exhaust valve lift. - Intake open/close: 17/34- Exhaust open/close: 51/11.5- Duration in/ex: 231/243- Valve lift in/ex: .518"/.521"- Valve lift TDC: .162"/.125"- TDC lobe centerline in/ex: 98.5/110- Overlap 28.5. 114"+ engines with high compression ratio. Requires high lift springs. RPM range 2.250-6.250Requires high-lift springs. The hotter version of the 508 for high RPM horsepower numbers. Nasty sound and aggressive pulling for 114+ inch motors with higher compression ratio. Works with stock throttle body but larger diameter produces higher peak power numbers. Okay with stock heads but works well well with ported heads. Heavy duty one-piece pushrods are recommended. Free breathing slip-on mufflers / exhaust and air cleaner are recommended for best results. Note: Requires high lift on stock cylinder heads. Note: Compatible with SE heads since these are equipped with high lift springs as standard. Note: Cam specs measured in the engine on the lifter @ 0.050 using the standard 1.61 rocker arm ratio.