Cylinder Head Specifications:; Combustion chamber volume: 87cc; Intake runner volume: 215cc; Exhaust runner volume: 175cc; Intake valve diameter: 2.11"; Exhaust valve diameter: 1.66"; Valve stem diameter: 11/32"; Valve guides: Manganese bronze; Deck thickness: 5/8"; Valve spring diameter: 1.46"; Valve spring maximum lift: .575"; Rocker stud: 7/16"; Guideplate: Hardended steel; Pushrod diameter: 5/16"; Valve angle: 14°; Exhaust port location: Stock Ram Air IV; Spark plug fitment: 14mm x 3/4 reach, gasket seat. These cylinder heads are designed for outstanding performance gains in 1962-79 389-455 c.i.d. Pontiac engines. They are patterned after the 1969-70 Ram Air IV Pontiac cylinder head. Performer heads #60579/#60575 are 50-state emissions legal for 1965-79 vehicles. They feature 87cc combustion chambers designed to maximize performance while using less expensive, low-octane fuel with a streetable 9.5:1 compression ratio. Our Performer RPM heads with the 72cc combustion chamber are for higher compression engines. Performer RPM #60509 is semi-machined and must be finished by a professional cylinder head porter. They include valve guides and seats installed with no intake pushrod holes. Performer RPM #60587 is not port matched or bowl blended and is NHRA accepted for Stock & Super Stock. INSTALLATION NOTE: These heads require Ram Air IV (round port) style exhaust manifolds or headers and Edelbrock head bolt kit #8549. Deck thickness: 5/8", rocker stud diameter: 7/16", pushrod diameter: 5/16" (width of slot in guide plate).

This Part Fits:

Year	Make	Model	Submodel
1965-1978	Pontiac	Bonneville	Base
1976-1978	Pontiac	Bonneville	Brougham
1965-1970,1978	Pontiac	Bonneville	Safari
1965-1967	Pontiac	Catalina	2+2
1965-1978	Pontiac	Catalina	Base
1971-1972	Pontiac	Catalina	Brougham
1965-1978	Pontiac	Catalina	Safari
1965-1970	Pontiac	Catalina	Ventura
1967-1970	Pontiac	Executive	Base
1967-1970	Pontiac	Executive	Safari
1968-1969	Pontiac	Firebird	400
1968-1977	Pontiac	Firebird	Base
1970-1974,1976	Pontiac	Firebird	Esprit
1970-1979	Pontiac	Firebird	Formula
1969-1979	Pontiac	Firebird	Trans Am
1973-1975	Pontiac	Grand Am	Base
1975-1977	Pontiac	Grand LeMans	Base
1975,1977	Pontiac	Grand LeMans	Safari
1965-1974,1976-1977	Pontiac	Grand Prix	Base
1975,1977	Pontiac	Grand Prix	LJ
1975-1977	Pontiac	Grand Prix	SJ
1971-1978	Pontiac	Grand Safari	Base
1971-1974	Pontiac	Grandville	Base
1975	Pontiac	Grandville	Brougham
1965-1966,1968-1973	Pontiac	GTO	Base
1970-1971	Pontiac	GTO	The Judge
1968-1977	Pontiac	LeMans	Base
1972-1974	Pontiac	LeMans	Luxury
1969-1970,1973-1975,1977	Pontiac	LeMans	Safari
1974	Pontiac	LeMans	Safari Luxury
1970-1977	Pontiac	LeMans	Sport
1971	Pontiac	LeMans	T37
1965-1966	Pontiac	Star Chief	Base
1966	Pontiac	Star Chief	Executive
1968,1970	Pontiac	Tempest	Base
1968	Pontiac	Tempest	Custom
1970	Pontiac	Tempest	GT
1968	Pontiac	Tempest	Safari