AFR 23° SBC Cylinder Head 245cc Competition Package Head, Spread Port Exhaust, 70cc Chambers

The AFR 245cc SBC Race Cylinder Head is the most advanced and powerful 60/40 head designed for small block Chevy applications. Featuring 100% CNC-machined intake runners, exhaust ports, and combustion chambers, these heads are capable of flowing an impressive 350 CFM at 0.800” lift. Built with titanium retainers and high-quality components, this competition-ready cylinder head ensures maximum performance for high-RPM race engines. The 60/40 valve spacing requires shaft-mounted rocker arms for optimal valvetrain geometry and includes extra machining for 3/8” pushrod clearance. The NPP (No Pushrod Pinch) design enhances airflow efficiency for uncompromised power delivery.

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 5.000") - AFR #7253
8mm Bead Lock Exhaust Valve (1.600" x 5.030") - AFR #7254
PAC #1225 Racing Springs (1.550” OD Solid Roller Dual Valve Drag Race Spring, 250 lbs. on seat, .800” max 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
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

Tested at 28" of water pressure on a Superflow 600 with a 4.155" bore size, intake 3/4" radius plate, and 1 7/8" curved exhaust pipe.

Lift	.200	.300	.400	.500	.550	.600	.650	.700	.800
Intake (CFM)	161	224	261	301	311	320	331	337	345
Exhaust (CFM)	128	165	214	228	237	238	243	245	250

Specifications & Features

Material: A356 Aluminum
Intake Port Volume: 245cc
Exhaust Port Volume: 80cc
Combustion Chamber Size: 70cc or 80cc
Valve Angle: 23°
Deck Thickness: .750"
Minimum Bore Diameter: 4.000"
Flat Mill: .006" per cc (65cc Maximum)
Angle Mill: .009" per cc (60cc Maximum)
Minimum Cross Sectional Area: 2.730 sq. in.
Spark Plug Dimensions: 14mm x .750" w/Gasket Seat

Important Notes

WARNING: These cylinder heads are designed for competition use only and are illegal for operation on any public highway, road, or park. Violations may result in fines of up to $37,500 per infraction, revocation of DMV registration, and loss of public roadway use rights. These heads are only legal for use on dedicated race vehicles.