{"product_id":"manley-chevrolet-big-block-exhaust-valve-kit-1-725in-head-dia-5-374in-o-a-length-0-3715in-stem","title":"Manley Chevrolet Big Block Exhaust Valve Kit - 1.725in Head Dia. 5.374in O\/A Length, 0.3715in Stem","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":44749971095752,"sku":"MAN11835-8","price":405.34,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0569\/0058\/3624\/files\/d9b0b2e5c48f9fcf643a62c8f93bf345L_af726906-3fee-4224-abef-31c060b8d241.jpg?v=1756566568","url":"https:\/\/coyotedirect.com\/products\/manley-chevrolet-big-block-exhaust-valve-kit-1-725in-head-dia-5-374in-o-a-length-0-3715in-stem","provider":"Coyote Direct ","version":"1.0","type":"link"}