AFR Partial CNC 265cc/ 109cc Oval Port Cylinder Head Pair BBC

Oval port cylinder heads provide strong mid-range airflow for street and race Big Block Chevy combinations. These cylinder heads use partial CNC porting in the intake runners, exhaust runners, and combustion chambers to improve airflow consistency for engines up to 468 cubic inches operating to 6,200 RPM. Cast from A356 aluminum, the cylinder heads reduce weight while maintaining thermal stability under load.

Features and Benefits:
- A356 aluminum construction reduces weight and manages heat
- 265cc oval intake ports support engines up to 468 cubic inches
- Partial CNC porting improves airflow consistency
- 109cc combustion chambers suit Big Block Chevy builds
- .375" raised exhaust ports improve exhaust flow path
- Perimeter bolt valve cover pattern fits compatible covers
- .750" deck thickness supports higher cylinder pressures

Specifications:
- Material: A356 aluminum
- Intake port volume: 265cc
- Intake port dimension: 2.030" H x 1.830" W x 1/2” radius
- Intake port location: stock
- Exhaust port volume: 132cc
- Exhaust port dimension: 1.770" H x 1.830" W
- Exhaust port location: .375” raised
- Combustion chamber size: 109cc
- Valve cover bolt pattern: perimeter bolt
- Valve angle: 24/4 degrees (intake), 15/4 degrees (exhaust)
- Valve spring pocket diameter: 1.725" OD
- Max valve spring pocket machining: 1.750" OD (warning: do not machine spring pad any deeper.)
- Deck thickness: 0.750”
- Minimum bore diameter: 4.125”

Vehicle Fitment:
- Fits Big Block Chevy Engines

Please Note: These products are illegal to operate on any public highway. This means any public paved or unpaved roadway or in a public park. These products are only legal if used on a dedicated racing vehicle. Violations are subject to a maximum penalty of $37,500 per violation per vehicle, revocation of registration by the DMV, loss of use on public right of ways, and proof of correction of the tampering.