Engineered to greatly increase performance and efficiency, the new Edelbrock E-Tec heads fit 302, 327, 350 and 400 c.i.d. small-block Chevys with “Vortec-style” intake manifolds. These powerful heads incorporate Edelbrock’s new high-quench combustion chamber which promotes a more uniform atomization of the air/fuel mixture for more power. Spark plugs have been positioned closer to the center of the cylinder for more efficient combustion. Both versions of the Edelbrock E-Tec heads come with one-piece stainless steel valves that are swirl-polished for maximum flow. They accept center-bolt or standard valve covers, work with most stock exhaust manifolds and have intake ports that are .200" taller than typical small-block heads. Exhaust port exits are raised .200". For maximum performance, match with one of the powerful Edelbrock Vortec intake manifolds.