AFR 12 LS3 Enforcer As Cast 238cc Int Runner, 72cc Chamber

AFR’s 238 LS3 Enforcer Cylinder Heads feature our Permanent Mold As-Cast Technology, ensuring extremely accurate and repeatable port locations and performance. The AFR 238cc LS3 Enforcer is the first Enforcer casting with a 100% AFR design. With a smaller valve and port, this head outflows your OE LS3 casting, delivering superior performance potential.

Designed for OEM engines operating below 6300 RPM, this budget-friendly cylinder head comes fully assembled with premium components found in AFRs high-end CNC-ported heads. These include PAC Racing springs, Viton valve seals, machined bead valve locks, hardened spring seats, and one-piece 8mm 21-4N/21-8N Stainless Steel valves. Also available as a bare casting for DIY enthusiasts.

Sold individuallytwo required per engine.

Basic Package Components

• 100% As Cast Intake, Exhaust, and Combustion Chambers
• Competition 5-angle Valve Job
• 8mm Bead Lock Intake Valve, 2.080″ x 5.200″ Overall Valve Length (AFR #7241)
• 8mm Bead Lock Exhaust Valve, 1.600″ x 5.205″ Overall Valve Length (AFR #7212)
• PAC Racing Spring 1.270″ OD Hydraulic Roller Dual Valve Spring, 155 lbs. on seat, .650″ max lift, Max RPM 7000-7200 (AFR #8017)
• 7 Steel Retainers (AFR #8514)
• 7 Bead Lock Valve Keepers (AFR #9007)
• Viton Valve Seals (AFR #6615)
• Hardened Valve Spring O.D Locator (AFR #8042)
• Rocker Rail Stand (AFR #6040)

Flow Chart Data

Flow Numbers (CFM) at 28 of water (Superflow 1020) – Bore Size: 4.060

Recommended Components

• Intake Port Gasket: Factory GM or Aftermarket
• Recommended Rockers: OEM w/ trunion upgrade or Yella Terra 6733 w/ 5132 Valve Cover Gasket
• Exhaust Port Gasket: GM #12558573
• Head Gasket: Cometic 4.160 Bore Size
• Head Bolts: ARP 134-3610 (AFR #6334)
• Head Studs: ARP #234-4317 (2004 & Later Blocks), ARP #234-4316 (Pre-2004 Blocks) (AFR #6335)
• Suggested Manifold: FAST 92mm or 102mm
• Spark Plug Starting Range: NGK TR55

Specifications & Features

• Material: A356 Aluminum
• Intake Port Volume: 238cc
• Exhaust Port Volume: 92cc
• Combustion Chamber Size: 72cc
• Valve Angle: 12
• Deck Thickness: .750″
• Minimum Bore Diameter: 4.000″