{"product_id":"manley-dart-big-block-pro-1-stock-length-11-32in-stem-dia-severe-duty-intake-valves-set-of-8","title":"Manley Dart Big Block Pro 1 Stock Length 11\/32in Stem Dia Severe Duty Intake Valves (Set of 8)","description":"Manley 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.","brand":"Manley Performance","offers":[{"title":"Default Title","offer_id":67646611259665,"sku":"MAN11817-8","price":301.95,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0919\/3681\/7425\/files\/639c017773af16048d25285e221903acL_717f693f-39ed-44d5-a11f-7f519de0dd79.jpg?v=1791206282","url":"https:\/\/autoshopactive.com\/products\/manley-dart-big-block-pro-1-stock-length-11-32in-stem-dia-severe-duty-intake-valves-set-of-8","provider":"Auto Shop Active","version":"1.0","type":"link"}