Latest Update About ; 15 18, Messagerie Neuf, Messagerie Sfr, Neuf Portail, Ma Messagerie Sfr, Edelbrock E-Street Cylinder Heads for Big-Block Chevy, Edelbrock has expanded their line of E-Street cylinder heads to include an application for oval port big-block Chevy’s. This new 290cc head is designed for entry-level street performance and offers high quality at an affordable price. Manufactured in the USA, these heads are made from A356 aluminum castings that are heat treated to T-6 specifications for superior strength and quality. Features include larger than stock (290cc) intake and (110cc) exhaust ports for improved engine efficiency; resulting in more horsepower, torque and increased mileage potential. Hardened spring cups help protect long-term wear along with the Heli-Coil® threaded inserts for exhaust flanges and rocker studs; these are the items that the lower-cost competitors leave out of their heads. These new heads are equipped with 7/16″ rocker studs and double valve springs to handle valve lifts up to .700″. The combustion chambers measure 110cc and their 2.19″ intake valve and 1.88″ exhaust valve combo produces great horsepower and torque. These E-Street Chevy Big Block heads are assembled with manganese bronze valve guides and stainless steel valves with hardened tips.