{"product_id":"manley-chevy-l83-5-3l-1-560in-head-diameter-pro-flo-severe-duty-exhaust-valve-single","title":"Manley Chevy L83 5.3L 1.560in Head Diameter Pro Flo\/Severe Duty Exhaust Valve (Single) - 12361-1","description":"\u003cp\u003eManley 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.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eProven fatigue strength for extreme performance\u003c\/li\u003e\n\u003cli\u003eChrome stems and hard tips enhance durability\u003c\/li\u003e\n\u003cli\u003eExotic alloys for superior tensile strength, reliability, and longevity\u003c\/li\u003e\n\u003cli\u003eSwirl polishing and machined faces improved airflow\/optimized efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSpecs\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eManley Valve\u003c\/li\u003e\n\u003cli\u003eExhaust, Valve-S\/D L83 53L 1.560, .3136 STEM\u003c\/li\u003e\n\u003cli\u003eExhaust, Valve-S\/D L83 5.3L 1.560, .3136 STEM\u003c\/li\u003e\n\u003cli\u003eO\/A Length: 5.208\u003c\/li\u003e\n\u003cli\u003eValve Length: 5.208\u003c\/li\u003e\n\u003cli\u003eValve Tip Length: 0.160\u003c\/li\u003e\n\u003cli\u003eTip Length: 0.160\u003c\/li\u003e\n\u003cli\u003eMargin Width: 0.065\u003c\/li\u003e\n\u003cli\u003eSeat Width: 0.110\u003c\/li\u003e\n\u003cli\u003eTop of Head: 18 Degree Dish\u003c\/li\u003e\n\u003cli\u003eValve Head Shape: 18 Degree Dish\u003c\/li\u003e\n\u003cli\u003eUnderhead Angle: 25.00\u003c\/li\u003e\n\u003cli\u003eUnderhead Radius: 7\/16\u003c\/li\u003e\n\u003cli\u003eValve Series: Severe Duty? Series\u003c\/li\u003e\n\u003cli\u003eValve Material: Stainless Steel\u003c\/li\u003e\n\u003cli\u003eValve Type: Exhaust\u003c\/li\u003e\n\u003cli\u003eProduct Type: Engine Exhaust Valve\u003c\/li\u003e\n\u003cli\u003eValve Quantity: 1\u003c\/li\u003e\n\u003cli\u003eEngine Valve Quantity: 1\u003c\/li\u003e\n\u003cli\u003eIndustry: Automotive\u003c\/li\u003e\n\u003cli\u003eOut of Stock Message: Call for Availability\u003c\/li\u003e\n\u003cli\u003eTitle: Manley Valve - Exhaust, Valve-S\/D L83 5.3L 1.560, .3136 STEM\u003c\/li\u003e\n\u003cli\u003eProp 65 Yes\/No: Yes\u003c\/li\u003e\n\u003cli\u003eProp 65 (C, R or CR): CR\u003c\/li\u003e\n\u003cli\u003eProp 65 - Short Label: Prop 65 Warning Label.JPG\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Manley Performance","offers":[{"title":"Default Title","offer_id":52481021837675,"sku":"MAN12361-1","price":37.64,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/9690\/4998\/files\/public_97dab662-98c6-469f-9de1-2ec26463e18a.jpg?v=1778202270","url":"https:\/\/www.raptorracing.com\/products\/manley-chevy-l83-5-3l-1-560in-head-diameter-pro-flo-severe-duty-exhaust-valve-single","provider":"Raptor Racing","version":"1.0","type":"link"}