SB Chevy, 70cc combustion chambers with straight plugs, 195cc Intake port

ED60739

60739

Performer RPM heads are perfect for street performance, daily drivers, street rods and muscle cars where seat-of-the-pants performance is needed. These heads give great torque and horsepower up to 6500 rpm. Designed for 302, 327, 350 and 400 cid small-block Chevy engines up to 1986, these Performer RPM cylinder heads are available fully assembled and ready to bolt on or bare for use with your own valve train components. Features include high-quality stainless steel 2.02" intake and 1.60" exhaust valves, choice of 64cc or 70cc combustion chambers and high flow 185cc intake and 65cc exhaust ports. Intake and exhaust runners are hand blended in the bowl area and the intake entries and exhaust exits are cnc profiled for increased air-flow. These heads include adjustable rocker stud and guide plate set-up for use with adjustable rockers. The casting is manufactured of A356 aluminium and heat treated to T6 spec for superior quality. An extra-thick 5/8" deck and Heli-coil threaded inserts variety of exhaust offer improved durability. Performer RPM cylinder heads are available with straight or angled spark plug configuration to fit a applications. To use stock stamped steel rockers on small-block Chevy heads, +.100" longer than stock. Small-block Chevy heads may not be used on engines with less than a 4.00" bore except with camshafts with less than .450" valve lift. Combustion chamber volume: 70cc Intake runner volume: 185cc Exhaust runner volume: 65cc Intake valve diameter: 2.02" Exhaust valve diameter: 1.60" Valve stem diameter: 11/32" Valve guides: Manganese bronze Deck thickness: 5/8" Valve spring diameter: 1.46" Valve spring maximum lift: .575" Rocker stud: 3/8" Guide plate: Hardened Steel Pushrod diameter: