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

The AFR 235cc SBC Race Cylinder Head is engineered for serious racing applications, delivering maximum performance with 100% CNC-machined intake runners, exhaust ports, and combustion chambers. Designed with a 60/40 valve spacing for optimal valve train geometry, these heads require shaft-mounted rocker arms but can accommodate .050 offset intake rockers for drag racing applications. Built with high-quality components, including titanium retainers and PAC Racing springs, these heads offer superior airflow and durability.

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, 2.125" x 5.00" long O.A.L. (AFR #7253)
8mm Bead Lock Exhaust Valve, 1.600" x 5.030" long O.A.L. (AFR #7254)
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)
10° Titanium Retainers 1.500” O.D x 1.120” I.D x .705” I.D (AFR #8505)
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)
Hardened Valve Spring I.D Locator 1.550” O.D x .780” I.D (AFR #8048)
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

Flow test conducted at 28" of water (pressure) on Superflow 600, Bore Size: 4.155", intake 3/4" radius plate exhaust, 1 7/8" curved pipe.

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

Specifications & Features

Material: A356 Aluminum
Intake Port Volume: 235cc
Exhaust Port Volume: 80cc
Combustion Chamber Size: 70cc or 80cc
Valve Angle: 23°
Deck Thickness: .750"
Minimum Bore Diameter: 4.000"

Legal Disclaimer

These products are illegal for operation on public highways. They are only legal for dedicated racing vehicles. Violations may result in penalties up to $37,500 per violation per vehicle.