{"product_id":"manley-big-block-ford-429-460-2-400in-diameter-5-725in-length-severe-duty-intake-valves-set-of-8","title":"Manley Big Block Ford 429-460 2.400in Diameter 5.725in Length Severe Duty Intake Valves (Set of 8)","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":51692034752785,"sku":"MAN11590-8","price":311.48,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0907\/7129\/2433\/files\/5f4b70fa0b8a870e0877005e4b8d1853_f9699770-4009-4324-8157-d547da350a88.jpg?v=1749579670","url":"https:\/\/emitperformance.com\/products\/manley-big-block-ford-429-460-2-400in-diameter-5-725in-length-severe-duty-intake-valves-set-of-8","provider":"Emit Performance Store","version":"1.0","type":"link"}