{"product_id":"manley-chevy-l83-5-3l-1-560in-head-diameter-pro-flo-severe-duty-exhaust-valve-set-of-8","title":"Manley Chevy L83 5.3L 1.560in Head Diameter Pro Flo\/Severe Duty Exhaust Valve (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":44839696728098,"sku":"MAN12361-8","price":301.07,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0590\/1231\/7218\/files\/9f3fe65eab22c1b800b67cb4ba0de39eL_3992ef0f-8c3a-4ae4-a8fe-c45ba7806b1c.jpg?v=1771323217","url":"https:\/\/shopjdm.com\/products\/manley-chevy-l83-5-3l-1-560in-head-diameter-pro-flo-severe-duty-exhaust-valve-set-of-8","provider":"ShopJDM","version":"1.0","type":"link"}