AFR 23° SBC Cylinder Head 227cc Competition Package Heads, Spread Port Exhaust, 75cc Chambers

AFR's 227cc "Race Ready" and "Competition" cylinder heads are designed for the most demanding performance applications. These heads feature 100% CNC ported intake, exhaust, and combustion chambers, ensuring maximum airflow and precision. Constructed from A356 aluminum castings and equipped with high-quality components throughout, these heads are optimized for serious racers. With a 60/40 valve spacing, they require shaft mount rocker arms for ideal valve train geometry and can be used with .050 offset intake rockers in drag race-specific setups.

Included Components

100% CNC Ported Combustion Chambers
100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
Competition 5-angle Valve Job

Key Components

8mm Bead Lock Intake Valve: 2.100" x 5.000" Overall Valve Length (AFR #7256)
8mm Bead Lock Exhaust Valve: 1.600" x 5.030" Overall Valve Length (AFR #7254)
PAC Racing Spring: 1.550" OD Solid Roller Dual Valve Spring, 220 lbs on seat, .710" max lift (AFR #8000)
10° Steel Retainers: 1.500" O.D x 1.120" I.D x .705" I.D (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: .600" O.D x .495" I.D (AFR #6612)
Ductile Iron Intake Valve Seats: 2.200" O.D x 1.750" I.D x.375" Deep (AFR #9060)
Ductile Iron Exhaust Valve Seats: 1.696" O.D x 1.325" I.D x .305" Deep (AFR #9070)
8mm Bronze Valve Guides: .502" O.D x 2.100" O.A.L (AFR #9051)

Performance Flow Chart

227cc Race Ready™ Flow Chart (Superflow 1020, 28” of water pressure):
Intake Flow: 148 cfm at .200" to 318 cfm at .700"
Exhaust Flow: 116 cfm at .200" to 237 cfm at .700"

227cc Competition Flow Chart (Superflow 1020, 28” of water pressure):
Intake Flow: 152 cfm at .200" to 329 cfm at .750"
Exhaust Flow: 120 cfm at .200" to 245 cfm at .750"

Specifications & Features

Material: A356 Aluminum
Intake Port Volume: 227cc
Exhaust Port Volume: 80cc
Combustion Chamber Size: 65cc or 75cc
Valve Cover Bolt Pattern: Perimeter Bolt
Valve Angle: 23°
Deck Thickness: .750"
Spark Plug Dimensions: 14mm x .750" w/Gasket Seat

Important Notes

Warning: These products are illegal to operate on any public highway. They are only legal if used on a dedicated racing vehicle. Violations are subject to a maximum penalty of $37,500 per violation per vehicle, revocation of registration by DMV, and loss of use on public right-of-ways.