Brodix 1021005 IK180 cylinder heads for Small Block Chevy engines. Assembled with 2.020in intake and 1.600in exhaust valves, 180cc intake runner, and 64cc chamber. Features 1.470in springs, straight plugs, and A-356 aluminum construction. Designed for mild street or hobby stock racing, offering performance and value with phosphorous bronze guides and ductile iron seats. Sold as a pair.