AFR Recommends for moderate street or street/strip applications with displacements up to 509 cubic inches, operating at or below 6500 RPM. The intake runners and exhaust ports are partially CNC machined, while the combustion chambers are fully CNC machining with a bowl blend. These 305cc Big B;ock Chevrolet magnum cylinder heads are capable of flowing 368 CFM at 0.700" of lift
|305cc BBC Full CNC Chamber|
Material : A356 Aluminum
Intake Port Volume : 305cc
Intake Port Dimension : 2.380"H x 1.680"W 11/32 Radius
Intake Port : Stock
Exhaust Port Volume : 132cc
Exhaust Port Dimension : 1.720"H x 1.920" W
Exhaust Port Location : .375" Raised
Combustion Chamber Size : Full CNC 121cc
Valve Cover Bolt : Pattern Perimeter Bolt
Valve : Angle 24°/4° Int, 15°/4° Exh
Valve Spring Pocket Diameter : 1.725" O.D
Max Valve Spring Pocket Machining : 1.750" O.D
Deck Thickness : .750"
Minimum Bore Diameter : 4.250"
Flat Mill : .006" per cc/ Maximum 114cc CNC Chamber
Angle Mill : .009" per cc/ Maximum 104cc as cast
Note:Angle mills might require a .120" Thick intake gasket.
Minimum Cross Sectional Area :2.993 sq. in.
Spark Plug Dimensions : 14mm x .750" w/Gasket Seat
** With some domed aftermarket pistons, it may be necessary to slightly clearance or modify the piston due to there more efficient heart shaped combustion chamber design. Most of the newer designed dome profiles will clear. AFR strongly recommends material be removed from the piston and not the cylinder head. Our combustion chamber shapes are very critical to flow and altering the cylinder head can adversely affect flow and power production. It is the customers responsibility to verify proper piston to head clearance.
*** Heads are designed for 3/8" pushrods. Larger pushrods will not fit without clearancing and is not recommended since some areas are very thin.
AFR recommends the use of .120" thick-wall pushrods.
AFR heads are available bare (without parts), call our tech line (714) 523-0530 for details.