These S&S® Super Stock® high performance cylinder heads are designed specifically for S&S® 4-1/8" bore V-Series engines for 1984-'99 HD® big twins. Heads are machined for the S&S® 4-1/8" cylinder stud pattern used on S&S® Special Application crankcases. 2.000" intake and 1.605" exhaust valves coupled with S&S® ports, supply plenty of air for these big motors. Machined for S&S® electric or manual compression releases. The manifold mounting surface machined to stock specifications so special length manifold/throttle body is required for engines that are not stock height. 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. Wrinkle black powder coat finish matches stock black engine components.