The Edelbrock part #79455 Big Block Chevy E-CNC 325 cylinder head is the ultimate in performance. These cylinder heads are fully CNC ported for maximum horsepower and torque, making them ideal for high-performance's street and light duty racing applications. They also feature high-quality lightweight valve springs and heavy duty hardware for maximum lift and maintain the stock exhaust port location. E-CNC 325 FOR B/B CHEVY (OVAL PORT) FEATURES: - Features 24.5 Deg x 4.4 Deg intake valve angle, 15.5 Deg x 4.2 Deg exhaust valve angle - Stock exhaust port locations and spark plug angles have been modified to produce a smooth flame front for increased fuel efficiency and maximum power - Cylinder heads are equipped with high-quality valve springs for valve lifts of up to .700" - Full CNC porting of the combustion chambers as well as the intake and exhaust runners this improves air-flow and overall performance potential - Equipped with valve springs for use in hydraulic roller applications - Combustion chamber size of 110cc