AFR 24° BBC Cylinder Head 290cc Oval Port Fully CNC Ported, 112cc Chambers, Competition Package, Assembled w/Hydraulic Roller Springs

The AFR 290cc BBC Oval Port Cylinder Head is the perfect choice for high-performance street or street/strip big block Chevy applications with displacements up to 509 cubic inches, operating at or below 6500 RPM. Designed with precision, this cylinder head features fully CNC-machined intake runners, exhaust ports, and combustion chambers, delivering superior airflow and power potential. With an impressive flow rate of 375 CFM at 0.700” lift, this head is engineered for serious performance enthusiasts.

Included Components

100% CNC Ported Combustion Chambers
100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
Competition 5-Angle Valve Job
11/32" Intake Valve, 2.250" x 5.500" O.A.L (AFR #7620)
11/32" Nail Head Exhaust Valve, 1.880" x 5.450" O.A.L (AFR #7630)
PAC Racing #1940 1.550” OD Hydraulic Roller Dual Valve Springs, 175 lbs. on seat, .725” max lift, Max RPM 6500-6700 (AFR #8002)
10° Steel Retainers 1.500" O.D x 1.120" I.D x .705" I.D (AFR #8511)
10° 11/32" Valve Keepers with Lashcap Recess (AFR #9005)
ARP 7/16" Rocker Studs Intake (AFR #6407)
ARP 7/16" Rocker Studs Exhaust (AFR #6406)
Adjustable 3/8" Guide Plates (AFR #6109)
11/32" Viton Valve Seals (AFR #6613)
Hardened Valve Spring I.D Locator 1.655" O.D x 1.565" I.D – For 8002 Spring (AFR #8044)
Intake Valve Seats 2.450" O.D x 1.950" I.D x .375" Deep (AFR #9065)
Exhaust Valve Seats 2.000" O.D x 1.580" I.D x .375" Deep (AFR #9064)
11/32" Intake Bronze Valve Guides .502" O.D x 2.10" O.A.L (AFR #9041)
11/32" Exhaust Bronze Valve Guides .502" O.D x 2.25" O.A.L (AFR #9042)

Performance Flow Chart (CFM)

Test conducted at 28" of water (pressure) on Superflow 1020 with a bore size of 4.310".

Lift (inches)	.200	.300	.400	.500	.550	.600	.650	.700
Intake	159	233	289	327	339	354	362	369
Exhaust	135	180	230	262	271	278	286	292

Technical Specifications

Material: A356 Aluminum
Combustion Chamber Size: 112cc
Valve Angle: 24°/4° Int, 15°/4° Exh
Intake Port Volume: 290cc
Exhaust Port Volume: 135cc
Deck Thickness: .750"
CARB Status: Not legal for sale or use on emission-controlled vehicles. Intended for dedicated race vehicles only.