{"product_id":"head-diameter-1-590-in-stem-diameter-0-3136-in-o-a-4-923-in-1","title":"Head Diameter: 1.590 in. - Stem Diameter: 0.3136 in. - O\/A : 4.923 in.","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","offers":[{"title":"Default Title","offer_id":52950753345830,"sku":"BBPB_11661-8","price":301.07,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0672\/5697\/5654\/files\/public_f3e1503f-4aac-4f93-8f01-b7d674cd1671.jpg?v=1775066605","url":"https:\/\/ossparts.com\/products\/head-diameter-1-590-in-stem-diameter-0-3136-in-o-a-4-923-in-1","provider":"Operational Speed Supply","version":"1.0","type":"link"}