{"product_id":"edelbrock-cylinder-head-pontiac-performer-rpm-72cc-for-hydraulic-roller-cam-complete-ea","title":"Edelbrock Cylinder Head Pontiac Performer RPM 72cc for Hydraulic Roller Cam Complete (Ea)","description":"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 \u0026amp; 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).","brand":"Edelbrock","offers":[{"title":"Default Title","offer_id":43835092992221,"sku":"EDE60595","price":1405.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0590\/3758\/1491\/products\/3602278431b510f3f06e9a5b33d9d66a.jpg?v=1683467164","url":"https:\/\/hellhoundperformance.store\/products\/edelbrock-cylinder-head-pontiac-performer-rpm-72cc-for-hydraulic-roller-cam-complete-ea","provider":"Hellhound Performance","version":"1.0","type":"link"}