AFR 23° SBC Cylinder Head 227cc Race Ready Heads, Spread Port Exhaust, 65cc Chambers

AFR’s 227cc "Race Ready" and "Competition" small block Chevy cylinder heads feature 100% CNC ported intake, exhaust, and combustion chambers. Constructed from high-quality A356 aluminum castings, these heads deliver outstanding airflow and durability. Designed with 60/40 valve spacing, they require shaft mount rocker arms for optimal valvetrain geometry, though .050 offset intake rockers can be used in drag race-only applications.

Included Components

100% CNC Ported Combustion Chambers
100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
Competition 5-angle Valve Job
8mm Bead Lock Intake Valve, 2.100" x 5.000" (AFR #7256)
8mm Bead Lock Exhaust Valve, 1.600" x 5.030" (AFR #7254)
PAC Racing Spring 1.550" OD Solid Roller Dual Valve Spring (AFR #8000)
10° Steel Retainers (AFR #8511)
10° Bead Lock Valve Keepers with lashcap recess (AFR #9009)
ARP 7/16" Rocker Studs (AFR #6405)
Adjustable 5/16" Guide Plates (AFR #6103)
Viton Valve Seals (AFR #6612)
Hardened Valve Spring I.D. Locator (AFR #8048)
Ductile Iron Intake & Exhaust Valve Seats (AFR #9060 & #9070)
8mm Bronze Valve Guides (AFR #9051)

227cc Race Ready™ Flow Chart

Lift	.200	.300	.400	.500	.550	.600	.650	.700
Intake	148	210	261	296	304	312	315	318
Exhaust	116	155	204	220	225	229	233	237

Specifications & Features

Material: A356 Aluminum
Intake Port Volume: 227cc
Intake Port Dimension: 2.200" H x 1.290" W
Exhaust Port Volume: 80cc
Exhaust Port Dimension: 1.430" H x 1.540" W
Combustion Chamber Size: 65cc or 75cc
Valve Angle: 23°
Deck Thickness: .750"
Minimum Bore Diameter: 4.000"
Flat Mill: .006" per cc (60cc Maximum)
Angle Mill: .009" per cc (55cc Maximum)
Spark Plug Dimensions: 14mm x .750" w/Gasket Seat

Important Compliance Notice

These products are illegal to operate on any public highway, including public paved or unpaved roads and public parks. Legal use is limited to dedicated racing vehicles. Violators are subject to fines up to $37,500 per violation, potential revocation of vehicle registration, and other penalties.