AFR 24° BBC 300cc Oval Port Fully CNC Ported, 112cc Chambers, Competition Package

The AFR 300cc BBC Oval Port Cylinder Head is designed for aggressive street, street/strip, or race big block Chevys with displacements up to 540 cubic inches, operating at or below 6800 RPM. Featuring 100% CNC-machined intake runners, exhaust ports, and combustion chambers, this head delivers superior airflow with 388 CFM at 0.700" lift. It’s the ultimate performance upgrade without transitioning to a rectangular port design.

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, 2.300" x 5.500" O.A.L (AFR #7626)
11/32" Nail Head Exhaust Valve, 1.880" x 5.450" O.A.L (AFR #7630)
PAC Racing Spring #1224 1.625 O.D. Solid Roller Dual Valve Spring, 275lbs on seat, .850" Maximum Lift (AFR #8031)
PAC Racing #1940 1.550" OD Hydraulic Roller Dual Valve Spring, 175 lbs. on seat, .725" Maximum Lift (AFR #8002)
10° Steel Retainers (AFR #8518, AFR #8511)
10° 11/32" Valve Keepers with Lashcap Recess (AFR #9005)
ARP 7/16" Rocker Studs Intake (AFR #6407) & Exhaust (AFR #6406)
Adjustable 3/8" Guide Plates (AFR #6109)
11/32" Viton Valve Seals (AFR #6613)
Hardened Spring Cup 1.740” O.D / 1.650” I.D (AFR #8046)
Intake & Exhaust Valve Seats (AFR #9065, AFR #9064)
11/32" Bronze Valve Guides (AFR #9041, AFR #9042)

Performance Flow Chart

Test conducted at 28" of water on Superflow 1020 with a 4.500" bore size, 3/4" radius plate exhaust, and 1 7/8" curved pipe.

Lift (in.)	.200	.300	.400	.500	.550	.600	.650	.700
Intake (CFM)	161	238	298	342	359	374	384	388
Exhaust (CFM)	139	191	234	266	275	289	294	298

Specifications & Features

Material: A356 Aluminum
Intake Port Volume: 300cc
Combustion Chamber Size: 112cc
Valve Angle: 24°/4° Int, 15°/4° Exh
Deck Thickness: .750"
Minimum Bore Diameter: 4.250"
Flat Mill: .006" per cc (Max 102cc)
Angle Mill: .009" per cc (Max 97cc, may require .120" intake gasket)
Spark Plug: 14mm x .750" w/Gasket Seat
CARB Status: Not legal for sale or use on emission-controlled vehicles. For race use only.