Brand: Airflow Research (AFR) Manufacturer's Part Number: 1691 Part Type: Cylinder Heads Product Line: AFR 245cc LSX Mongoose Strip Cylinder Heads Automotive Fittings Part Number: AFR-1691 Combustion Chamber Volume (cc): 73 Intake Runner Volume (cc): 245cc Exhaust Runner Volume (cc): 88cc Cylinder Head Style: Bare Cylinder Head Material: Cast aluminum Intake Port Shape: Cathedral Intake Valve Diameter (in.): 2.165 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: Standard Intake Valves Included: No Exhaust Valves Included: No Exhaust Valve Diameter (in.): 1.600 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 Accessory Bolt Holes Drilled: Yes Intake Valve Angle: 15 Exhaust Valve Angle: 15 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. Notes: Must be used on 4 in. bore or larger. Description: Maximize 4.000 in. and larger bore combinations with AFR 245cc LSX Mongoose Strip cylinder heads. These aluminum cylinder heads feature 100 percent CNC-ported chambers, intake, and exhaust ports, and use A356 aluminum castings. They're also equipped with AFR's 3/4 in. thick deck and thicker port and combustion surfaces. designed for the LSX platform, these max effort cathedral port heads are recommended for race applications or radical "Pro Street" builds with displacements up to 454 cu. in., operating at or below 6800 rpm. Run AFR 245cc LSX Mongoose Strip cylinder heads—and get ready to devour a Cobra, Viper, or any other venomous contestant!