Brand: Airflow Research (AFR) Manufacturer's Part Number: 1200 Part Type: Cylinder Heads Product Line: AFR 220cc SBC Eliminator Racing Heads Automotive Fittings Part Number: AFR-1200 Combustion Chamber Volume (cc): 65 Intake Runner Volume (cc): 220cc Exhaust Runner Volume (cc): 80cc Cylinder Head Style: Assembled Cylinder Head Material: Cast aluminum Intake Port Shape: Rectangular Intake Valve Diameter (in.): 2.100 in. CNC-Machined Combustion Chamber: Yes CNC-Machined Intake Runner: Yes CNC-Machined Exhaust Runner: Yes Combustion Chamber Style: Heart Intake Port Location: Standard Exhaust Port Shape: Round Exhaust Port Location: Raised Spark Plug Style: Angle Intake Valves Included: Yes Exhaust Valves Included: Yes Exhaust Valve Diameter (in.): 1.600 in. Valve Springs Included: Yes Maximum Valve Lift (in.): 0.710 in. Camshaft Style: Solid roller Outside Diameter of Outer Spring (in.): 1.550 in. Damper Spring Included: Yes Number of Springs Per Valve: Single Retainers Included: Yes Retainer Material: Chromoly steel Locks Included: Yes Lock Style: 10 degree Valve Stem Seals Included: Yes Valve Stem Seal Style: Positive stop Rocker Arm Studs Included: Yes Rocker Arm Nut Thread Size: 7/16 in.-20 Rocker Arms Included: No Rocker Arm Nuts Included: No Guideplates Included: Yes Guideplate Pushrod Size: 5/16 in. Valve Cover Mounting Style: Perimeter bolt Accessory Bolt Holes Drilled: Yes Intake Valve Angle: 23 Exhaust Valve Angle: 23 Valve Guides Included: Yes Valve Guide Material: Manganese bronze Valve Seats Machined: Yes Valve Seat Machine Style: 5-angle intake/3-angle exhaust Valve Seat Material: Ductile iron Cylinder Head Color: Natural Steam Holes Drilled: No Oiling Style: Through head Machined for O-Ring: No Heat Crossover: No Remanufactured: No Quantity: Sold as a pair. Description: Race-ready AFR 220cc SBC Eliminator racing heads feature 100 percent CNC-ported intakes with greater detail. They also come with 100 percent CNC-ported combustion chambers and 80cc exhaust ports with a 3/4 in. thick head deck (ideal for nitrous or blower applications). Standard valves are lightweight 8mm, 2.080 in. intakes and 1.600 in. exhausts with AFR's hardened ductile iron interlocking valve seats. The valve springs included are intended for use on roller camshafts. They also offer exceptional flow characteristics, a 23 degree valve angle, and standard valve spacing. These cylinder heads are perfect for 350 to 400 c.i.d. engines in bracket drag cars, sportsman oval trackers, and highly modified street-class cars operating between 3,000 and 7,500 rpm (higher rpm ranges are possible, depending on the combination of parts).