{"product_id":"manley-chevrolet-big-block-exhaust-valve-kit-1-940in-head-dia-5-422in-o-a-length-0-3415in-stem-1","title":"Manley Chevrolet Big Block Exhaust Valve Kit - 1.940in Head Dia. 5.422in O\/A Length, 0.3415in 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":47839829229794,"sku":"MAN11803-8","price":452.49,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0748\/5004\/2082\/files\/639c017773af16048d25285e221903acL_f767a346-8672-4d1b-9388-14b4f621c547.jpg?v=1780097519","url":"https:\/\/raceclub.us\/products\/manley-chevrolet-big-block-exhaust-valve-kit-1-940in-head-dia-5-422in-o-a-length-0-3415in-stem-1","provider":"Race Club ","version":"1.0","type":"link"}