These S&S® Super Stock® high performance cylinder heads are designed specifically for late production S&S® T124 long block engines for 1999-'05 HD® big twins and 1999-'05 engines with S&S® 124" Hot Set Up Kit installed. 2.000" intake and 1.605" exhaust valves coupled with S&S® ports, supply plenty of air for these big motors. The manifold mounting surface specially machined to compensate for the slighty taller cylinders, so a stock length manifold/throttle body will fit. S&S® High performance valve springs allow the installation of camshafts with up to .650" lift. Compatible with stock rocker boxes, exhaust, and intake manifolds.