{"product_id":"manley-chevrolet-small-block-exhaust-valve-kit-1-625in-head-dia-5-640in-o-a-length-0-3110in-stem-1","title":"Manley Chevrolet Small Block Exhaust Valve Kit - 1.625in Head Dia. 5.640in O\/A Length, 0.3110in 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":51540204618022,"sku":"MAN11399-8","price":318.23,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0913\/0488\/6566\/files\/9f3fe65eab22c1b800b67cb4ba0de39eL_758802d6-1e14-4253-8edf-694ea2d582a5.jpg?v=1760016016","url":"https:\/\/burkkenautoparts.com\/products\/manley-chevrolet-small-block-exhaust-valve-kit-1-625in-head-dia-5-640in-o-a-length-0-3110in-stem-1","provider":"Burkken Auto Parts","version":"1.0","type":"link"}