AFR 24° BBC Cylinder Head 265cc Oval Port - Race Ready

The AFR 265cc BBC Oval Port Cylinder Head is a high-performance, cost-effective upgrade compared to re-worked factory Big Block Chevy cylinder heads. Featuring partially CNC-machined intake runners, exhaust ports, and combustion chambers, this head is designed for exceptional flow and performance. With the ability to flow 354 CFM at 0.650" lift, it is an excellent choice for street, street/strip, and towing applications, supporting displacements up to 468 cubic inches operating at or below 6200 RPM.

Included Components

75% CNC Ported Exhaust Ports (Bowl Blend), 75% CNC Chambers
80% CNC Ported Intake Ports (Bowl Blend)
Competition 5-angle Valve Job
11/32" Intake Valve, 2.190" x 5.460" Overall Valve Length – AFR #7601
11/32" Nail Head Exhaust Valve, 1.880" x 5.450" Overall Valve Length – AFR #7630
PAC Racing Springs (Options: Solid Roller & Hydraulic Roller) – AFR #8000 / #8002
10° Steel Retainers – AFR #8511
10° 11/32" Valve Keepers – AFR #9005
ARP 7/16" Rocker Studs (Intake & Exhaust) – AFR #6407 / #6406
Adjustable 3/8" Guide Plates – AFR #6109
11/32" Viton Valve Seals – AFR #6613
Hardened Valve Spring Cup & Locator – AFR #8044 / #8048
Intake & Exhaust Valve Seats – AFR #9065 / #9064
11/32" Bronze Valve Guides (Intake & Exhaust) – AFR #9041 / #9042

Performance Flow Data

Flow tests were conducted at 28" of water using a Superflow 1020 with a bore size of 4.310".

Lift	Intake (Partial CNC)	Exhaust (Partial CNC)	Intake (Full CNC)	Exhaust (Full CNC)
.200"	154 CFM	127 CFM	164 CFM	135 CFM
.300"	218 CFM	164 CFM	236 CFM	190 CFM
.400"	278 CFM	200 CFM	291 CFM	230 CFM
.500"	323 CFM	230 CFM	326 CFM	258 CFM
.550"	330 CFM	250 CFM	330 CFM	265 CFM
.600"	333 CFM	255 CFM	335 CFM	274 CFM
.650"	335 CFM	260 CFM	340 CFM	280 CFM

Technical Specifications

Material: A356 Aluminum
Intake Port Volume: 265cc
Exhaust Port Volume: 132cc
Combustion Chamber Size: 109cc (Partial CNC), 112cc (Full CNC)
Valve Angle: 24°/4° Int, 15°/4° Exh
Deck Thickness: 0.750"
Minimum Bore Diameter: 4.125"
Spark Plug Dimensions: 14mm x .750" w/Gasket Seat

Performance & Compatibility

This cylinder head is ideal for applications requiring high-velocity airflow and strong torque output. Perfect for street, street/strip, and towing applications, it supports Big Block Chevy engines up to 468 cubic inches running at 6200 RPM or lower.

CARB Compliance Notice

**These products are illegal to operate on any public highway and are only legal for use on dedicated racing vehicles. Violators may face penalties, including fines up to $37,500 per violation, vehicle registration revocation, and proof of correction.**