S&S Super Stock Cylinder Heads For Harley Twin Cam Enhance your vehicle's performance effortlessly with these heads, compatible with both stock and aftermarket pistons. Ideal for those seeking additional power without extensive modifications, these heads simply bolt on for immediate impact. Although they perform well with stock parts, pairing them with a quality exhaust system, air cleaner, and a more aggressive camshaft will maximize their potential, thanks to the high-lift springs installed by S&S. While not mandatory, adjustable pushrods complement these upgrades well. Remember to include gaskets in your setup. Features: High port flow gives great performance now, and more later when additional upgrades are done Heads are fully assembled with springs and valves, and are available in silver or wrinkle black powder-coat Compression ratios vary depending on cylinder heads chosen, pistons used and engine displacement The 79cc combustion chamber provides a slightly higher than stock, which makes most performance cams work better 79cc heads work great with stock motors for 88 to 103 motors 1.940 intake and 1.575 exhaust valve and springs for up to .640 lift Heads accept OEM rocker boxes Heads are machined for compression releases (sold separately) S&S rocker boxes required when using S&S compression releases Do not include rocker arm components, intake manifold, gaskets or head bolts (requires eight long OEM length head bolts) Compatible with stock rocker boxes, exhaust, and intake manifolds Sold in pairs Made in the USA