AFR 24° BBC Cylinder Head 325cc Partially CNC Ported, 117cc Chambers, Race Ready

The AFR 325cc BBC Rectangle Port Cylinder Head is designed for aggressive street or street/strip big block Chevy applications with displacements up to 540 cubic inches, operating at or below 6800 RPM. Featuring partially CNC-machined intake and exhaust ports, and combustion chambers available with partial or full CNC machining with a bowl blend, this cylinder head delivers exceptional performance. Capable of flowing 390 CFM at 0.700" of lift, it is an excellent choice for high-performance engines.

Included Components

50% CNC Ported Combustion Chambers
20% CNC Ported Exhaust Ports
30% 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 #7631)
PAC Racing #1224 1.625” OD Solid Roller Dual Valve Spring, 275 lbs. on seat, .850” max lift, 7400-7600 RPM (AFR #8031)
10° Steel Retainers, 1.500" O.D x 1.168" I.D x .844" I.D (AFR #8518)
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 Spring Cup 1.740" O.D / 1.650" I.D (AFR #8046)
Intake Valve Seats 2.450" O.D x 2.000" 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)

Flow Chart (325cc w/ 100% CNC Chamber)

Lift (in)	.200	.300	.400	.500	.600	.700
Intake (CFM)	155	227	281	319	346	368
Exhaust (CFM)	135	195	240	254	262	266

Specifications & Features

Material: A356 Aluminum
Intake Port Volume: 325cc
Combustion Chamber Size: 117cc (As Cast) / 121cc (Full CNC)
Valve Angle: 24°/4° Intake, 15°/4° Exhaust
Deck Thickness: .750"
Spark Plug Dimensions: 14mm x .750" w/Gasket Seat

CARB Compliance

NOTICE: These products are illegal to operate on any public highway. They are legal only for use on dedicated racing vehicles. Violations are subject to penalties, loss of registration, and proof of correction of tampering.