{"product_id":"manley-chevrolet-big-block-1-940in-head-dia-6-400in-oal-0-3415in-stem-exhaust-valve-single","title":"Manley Chevrolet Big Block 1.940in Head Dia. \/ 6.400in OAL \/ 0.3415in Stem \/ Exhaust Valve - Single","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":44029499965505,"sku":"MAN11583-1","price":50.18,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0553\/2637\/6001\/files\/f9b5e32303fea85f64f9fc13ba07de41L_96f80b01-0eac-4f5a-9ce4-ca4422e1c316.jpg?v=1780981302","url":"https:\/\/shop.kingsperformance.com\/en-gb\/products\/manley-chevrolet-big-block-1-940in-head-dia-6-400in-oal-0-3415in-stem-exhaust-valve-single","provider":"Kings Performance","version":"1.0","type":"link"}