AFR largest and best flowing Big Block Chevrolet cylinders heads, these cylinder heads feature 100% CNC machined intake runners, exhaust ports and combustion chambers. Best suited for +540 cubic inch large displacement racing engines, operating at or below 7600 RPM. Equipped with Titanium retainers and high quality components, these heads are capable of flowing 456 CFM at 0.900" of lift.
Material : A356 Aluminum
Intake Port Volume : 385cc
Intake Port Dimension : 2.565"H x 1.810"W x 15/32 Radius
Intake Port : Stock
Exhaust Port Volume : 135cc
Exhaust Port Dimension : 1.780"H x 2.025" W
Exhaust Port Location : .375" Raised
Combustion Chamber Size : Full CNC 122cc
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 : 3.890 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.