S&S Cycle Camshaft Kit - 640 Gear Drive - Twin Cam '07-'17 | Dyna '06903960983 Product Description For 103 110 CI engines Strongest from 3000 6000 rpm Compression ratios from 10. 5: 1 to 11. 5: 1 Improves valve timing accuracy by eliminating timing chain lash Includes camshaft, inner and outer gears, gear cover gasket, oil passage block off kit, retaining ring, and o ring Notes High lift springs and adjustable pushrods required.