Brodix 2208100 SR20 cylinder head for Big Block Chevy engines. CNC ported, assembled with 2.400in intake and 1.800in exhaust valves, 440cc intake runner, and 95cc chamber. Features 1.645in springs, straight plugs, and A-356 aluminum construction. Flows 507 cfm intake and 335 cfm exhaust, designed for high-performance racing. Requires specific pistons and shaft rockers. Sold as each.