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 AFR’s 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 individually—two 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”

Lift (in)	.200	.300	.400	.500	.550	.600	.650
Intake (CFM)	157	229	276	307	315	308	308
Exhaust (CFM)	112	152	182	204	209	215	217

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