Cylinder Head Style: Bare Cylinder Head Material: Aluminum Cylinder Head Finish: Natural Combustion Chamber Volume (cc): 72 CNC-Machined Combustion Chamber: No Intake Runner Volume (cc): 215cc Exhaust Runner Volume (cc): 175cc CNC-Machined Intake Runner: No CNC-Machined Exhaust Runner: No Intake Port Location: Standard Exhaust Port Shape: Ram Air IV Exhaust Port Location: Standard Intake Valves Included: No Intake Valve Diameter (in): 2.110 in. Exhaust Valves Included: No Exhaust Valve Diameter (in): 1.660 in. Valve Springs Included: No Damper Spring Included: No Retainers Included: No Locks Included: No Valve Stem Seals Included: No Rocker Arm Studs Included: No Rocker Arms Included: No Rocker Arm Nuts Included: No Guideplates Included: No Valve Cover Mounting Style: Perimeter bolt Accessory Bolt Holes Drilled: Yes Intake Valve Angle: 14 Valve Guides Included: Yes Valve Guide Material: Manganese bronze Valve Seats Machined: No Valve Seat Material: Ductile iron Steam Holes Drilled: No Oiling Style: Through pushrod Machined for O-Ring: No Heat Crossover: Yes Quantity: Sold individually. Notes: EDL-60517 is not port matched or bowl blended and is NHRA approved for Stock and Super Stock (except 1968-1969 W-30). Head bolt holes drilled for stock 7/16" bolts, but can be easily modified for 1/2" bolts or studs by drilling the 1/2" counterbore. Aftermarket 7/16"-stud rocker arms and 3/8" hardened pushrods required. Will fit 350-403 Oldsmobile with Edelbrock manifold EDL-7111 only (port matching required). These heads require Ram Air IV (round port) style exhaust manifolds or headers and Edelbrock head bolt kit 8549.