{"product_id":"manley-performance-11563-8","title":"Manley Performance Manley Big Block Chevrolet 1.880 Head Dia. 5.354 O\/A Length Severe Duty Exhaust Valves - Set of 8","description":"\u003cp\u003eManley Severe Duty® Valves deliver the ultimate in strength, reliability, and high-performance durability. Engineered for extreme gasoline engine temperatures, these valves are crafted from exclusive materials (XH-428 for exhaust and NK-844 for intake), offering unmatched tensile strength compared to competitive alloys. In fatigue testing at 40,000 psi and 1400°F, Manley exhaust valves endured 100 million cycles, while competitors failed after just 100,000, proving a 1,000× longer fatigue life. Each valve features chrome stems, hard tips, and swirl-polished underheads with fully machined combustion faces for superior airflow, efficiency, and wear resistance. Built for those who demand race-winning strength and precision, Manley Severe Duty® Valves set the industry standard for performance and endurance.\u003c\/p\u003e\u003cp\u003eGenuine Manley Performance. Part number 11563-8.\u003c\/p\u003e\u003cp\u003eShips from US warehouse.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWARNING:\u003c\/strong\u003e California Proposition 65 — this product can expose you to chemicals known to the State of California to cause cancer or reproductive harm.\u003c\/p\u003e","brand":"Manley Performance","offers":[{"title":"Default Title","offer_id":48718731182305,"sku":"11563-8","price":301.07,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0842\/7608\/4961\/files\/639c017773af16048d25285e221903acL_92ec0090-dcb7-47c1-912b-60941008f545.jpg?v=1784697192","url":"https:\/\/mlperformanceusa.com\/products\/manley-performance-11563-8","provider":"ML Performance USA","version":"1.0","type":"link"}