{"product_id":"manley-chevrolet-big-block-extreme-duty-exhaust-valve-5-522in-overall-l-1-900in-diameter-set-of-8","title":"Manley Extreme Duty Exhaust Valves – Chevrolet Big Block | Set of 8","description":"\u003cp\u003eFor Chevrolet Big Block cylinder-head work, this Manley Extreme Duty exhaust valve listing groups the available dimensional choices under one application-specific product family. The parent listing is distinguished by \u003cstrong\u003eSet of 8\u003c\/strong\u003e, which should be cross-checked against the rest of the engine combination.\u003c\/p\u003e\u003cp\u003eThe correct Chevrolet Big Block valve is the one that matches the finished head. Stem clearance, seat contact, installed height, spring package, and keeper location should all be checked during assembly.\u003c\/p\u003e\u003ch3\u003eKey Product Details\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Chevrolet Big Block\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManley Series:\u003c\/strong\u003e Extreme Duty\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eValve Position:\u003c\/strong\u003e Exhaust\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTitle Specification:\u003c\/strong\u003e Set of 8\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 12739-8\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003ePackage Quantity\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eSet of 8 valves.\u003c\/strong\u003e The selected configuration is supplied as a 8-piece valve package. This quantity applies to the selected Manley SKU family shown on this product page.\u003c\/p\u003e\u003ch3\u003eSelection \u0026amp; Fitment Notes\u003c\/h3\u003e\u003cp\u003eUse the finished cylinder-head setup as the authority for selection. Oversize valves or alternate lengths may require machining and can affect installed height and valvetrain geometry.\u003c\/p\u003e\u003cp\u003e\u003cem\u003eProfessional engine assembly and measurement are recommended. Product specifications should be confirmed against the selected Manley part number and the requirements of the exact engine build.\u003c\/em\u003e\u003c\/p\u003e","brand":"Manley Performance","offers":[{"title":"Default Title","offer_id":50207044600058,"sku":"MAN12739-8","price":514.08,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0325\/6352\/7739\/files\/1ecc177028ebb28898eba0253019ba05L_6c5ab6e4-60c5-40e8-96f5-45fc42faf478.jpg?v=1787979081","url":"https:\/\/lgcracing.com\/products\/manley-chevrolet-big-block-extreme-duty-exhaust-valve-5-522in-overall-l-1-900in-diameter-set-of-8","provider":"Legacy Racing","version":"1.0","type":"link"}