AFR 23° SBC Cylinder Head 235cc Competition Package Heads, Standard Exhaust, 80cc Chambers

The AFR 23° SBC 235cc Competition Package Heads are designed for high-performance drag racing applications. Built with precision CNC-machined intake runners, exhaust ports, and combustion chambers, these heads are the perfect choice for optimizing engine efficiency and power. Equipped with titanium retainers, PAC Racing Springs, and high-quality components, they feature a 60/40 valve spacing for superior valve train geometry. These heads are compatible with shaft-mounted rocker arms and can be used with .050 offset intake rockers for specialized drag race setups.

Included Components

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

Valve and Spring Components

Intake Valve: 8mm Bead Lock, 2.125" x 5.00" O.A.L. - AFR #7253
Exhaust Valve: 8mm Bead Lock, 1.600" x 5.030" O.A.L. - AFR #7254
Valve Springs: PAC Racing Springs, 1.550" OD, Solid Roller Dual Drag Race Spring, 250 lbs on seat, .800" maximum lift, Max RPM 8000-8200 - AFR #8001
Titanium Retainers: 10° 1.500” O.D x 1.120” I.D x .705” I.D - AFR #8505
Bead Lock Valve Keepers: 10° with lash cap recess - AFR #9009
Rocker Studs: ARP 7/16" - AFR #6405
Adjustable Guide Plates: 5/16" - AFR #6103
Viton Valve Seals: .600" O.D x .495" I.D - AFR #6612
Valve Spring I.D Locator: Hardened, 1.550” O.D x .780” I.D - AFR #8048
Valve Seats: Ductile Iron, Intake 2.200" O.D x 1.750" I.D x.375" Deep, Exhaust 1.696" O.D x 1.325" I.D x .305" Deep - AFR #9060 / AFR #9070
Bronze Valve Guides: 8mm, .502" O.D x 2.100" O.A.L - AFR #9051

Performance Flow Chart

The 235cc Competition heads deliver impressive flow numbers, tested at 28" of water on Superflow 600:

Lift	Intake	Exhaust
.200	159	120
.300	221	165
.400	261	214
.500	295	228
.550	311	237
.600	318	238
.650	327	243
.700	331	245
.800	336	250

Specifications & Features

Material: A356 Aluminum
Intake Port Volume: 235cc
Intake Port Dimensions: 2.200" H x 1.290" W, 5/16 Radius
Exhaust Port Volume: 80cc
Combustion Chamber Size: 70cc or 80cc
Valve Cover Bolt Pattern: Perimeter Bolt
Valve Angle: 23°
Deck Thickness: .750"
Minimum Bore Diameter: 4.000"
Spark Plug Dimensions: 14mm x .750" w/Gasket Seat

Legal Notice

WARNING: These products are illegal to operate on any public highway, including public paved or unpaved roadways or in a public park. They are only legal for use on dedicated racing vehicles. Violations may result in penalties up to $37,500 per violation per vehicle, revocation of vehicle registration by DMV, and loss of use on public right-of-ways.