{"product_id":"assembled-aluminum-cylinder-head-for-oldsmobile-big-block","title":"Assembled Aluminum Cylinder Head for Oldsmobile Big-Block","description":"The Speedmaster cylinder head set provides an aluminum performance upgrade for Oldsmobile 400, 425, and 455 big-block engines. Engineered for durability and improved thermal efficiency, these cast aluminum heads feature 77cc combustion chambers and 188cc intake runners, offering a robust foundation for building high-output Oldsmobile platforms.\n\nTechnically specified for hydraulic flat tappet camshafts, these assembled heads come ready with dual springs, chromoly steel retainers, and 10-degree locks. Key assembly specifications include a maximum valve lift capacity of 0.615 inches and 3-angle valve seats machined from ductile iron to ensure effective sealing and longevity. The ports feature a standard location with rectangular intake and square exhaust profiles.\n\nInstallation requires attention to component compatibility, as rocker arm studs, rocker arms, rocker arm nuts, and guideplates are not included. The cylinder heads utilize a center and perimeter bolt pattern for valve cover mounting and include drilled accessory bolt holes. These heads are sold as a complete pair to ensure balanced engine performance.","brand":"Speedmaster","offers":[{"title":"Default Title","offer_id":52664179982648,"sku":"PCE281.2152","price":1179.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0970\/4895\/3144\/files\/685589987.jpg?v=1784334827","url":"https:\/\/store.motormia.co\/products\/assembled-aluminum-cylinder-head-for-oldsmobile-big-block","provider":"MOTORMIA","version":"1.0","type":"link"}