Years of research and development have been invested to bring you the ultimate in bolt on performance for your Big Block Chevrolet. Airflow Research is proud to introduce our new line of Magnum BB Chevy Aluminum cylinder heads. All AFR Big Block heads feature the highest flow numbers in their class. With highly efficient port designs outflow the competition at every lift-point, even those with considerably larger runner volumes. An exclusive new combustion chamber design provides impressive swirl figures and help these heads generate big low and mid-lift airflow numbers. Considerable time has been spent to bring you a cylinder head which maximizes the entire flow curve, not just the big peak numbers. This aids in a much better ''cylinder fill'' and dramatically increases engine ''average'' airflow consumption (also spelled Horsepower!) The high velocity port designs help enhance engine acceleration as well as torque output. Structural features like the trademark 3/4'' head deck (a must for blown or nitrous engines), reinforced rocker stud bosses, and thick wall runners provide unparalleled durability, helping to create the strongest Big Block Chevy castings available today. Both intake and exhaust valve angles have been rolled two degrees to improve flow characteristics and provide a more efficient burn in the combustion chamber. Fully CNC ported competition packages are offered for intake port volumes of 305, 315, 325, 335, 345, 357, 377 and 385cc's, one of which is sure to provide a solution for any rpm or cubic inch requirement. AFR's fully CNC ported head will be 121cc's, with 114cc chambers as an option. Premium stainless steel one piece valves, chrome silicone 1.550''/1.625'' roller springs, and 10 degree chrome moly steel locks and retainers will come standard. Finally, a world class, true bolt-on performance piece for your Big Block Chevy, with no special parts required.