The Edelbrock part 79895 Small Block Chevy E - CNC cylinder head offers the ultimate performance. This cylinder head is fully CNC ported for maximum horsepower and torque, making them ideal for high - performance's street and racing applications. They also feature high - quality lightweight valve springs and heavy duty hardware for maximum lift. E - CNC SB CHEVY FEATURES - Features fully CNC machined intake ports, combustion chambers and exhaust ports for improved performance - Maintains the stock 23deg valve angle and intake flange bolt pattern for use with 1986 and earlier intake manifolds - Delivers up to 30 - 60 horsepower over the Performer RPM Cylinder Head - 61205 61209 features 716 studs and angled spark plugs - Ideal for high Performance's street and racing applications