1966 1967 1968 1969 1970 1971 1972 1973 1974 ALL CYLINDER HEAD

Part Number: 12480021

ALL  CYLINDER HEAD - Part Number 12480021
Cylinder Head SB2.2 Aluminum. Aluminum cylinder head designed for NASCAR-style stock car racing. It has "mirror" design intake ports and all eight ports are angled toward the center of the engine, making this a perfect choice for single four-barrel applications. Spark plug holes were moved toward the bore center for greater combustion efficiency. This head is designed for aftermarket shaft-mounted rocker arms and valve spring pads are large enough to use 1.625-inch springs. The combustion chambers are 48cc, which allow a 12.1:1 compression ratio with flat-top pistons. The valve guide machining has been reduced to only 3/8-inch. This head has been updated for tighter tolerances. The port core locations are improved by using a dry sand-casting process. The head is X-ray inspected and hot isostactic pressed to improve mechanical properties and remove porosity. A precision T-washer has been installed in all four center head bolt bosses for optimal contact between the washer and cylinder head bolt column, which reduces deformation under higher fastener loads. Physical Specifications: Intake Runner Volume: 287cc Exhaust Runner Volume: 109cc Combustion Chamber Volume: 54cc Intake Valve: 2.190 dia x 5.640 Length Exhaust Valve: 1.625 dia x 5.640 Length Intake Valve Angle: 11 deg x 4 deg Exhaust Valve Angle: 8 deg Intake Port Opening at Gasket: 2.15 h x 1.55 w Distance from floor to deck at gasket: 1.9 Intake Min. Cross Sectional Dim.: 3065 sq in. GM Performance Parts cylinder heads are created with GM premium-engineering, then cast and machined to our exacting manufacturing standards. GMPP cylinder heads are available as bare castings or complete cylinder head from service replacement castings to all-out competition applications.
SB2.2 Aluminum 1966 1967 1968 1969 1970 1971 1972 1973 1974

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