{"product_id":"manley-chevy-ls-6-head-small-block-severe-duty-pro-flo-exhaust-valves-set-of-8","title":"Manley Chevy LS-6 Head Small Block Severe Duty\/Pro Flo Exhaust Valves (Set of 8) - 11677-8","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\u003eHead Diameter: 1.600 in\u003c\/li\u003e\n\u003cli\u003eStem Diameter: .3136 in\u003c\/li\u003e\n\u003cli\u003eO\/A : 4.923\u003c\/li\u003e\n\u003cli\u003eManley Valve\u003c\/li\u003e\n\u003cli\u003eExhaust, Valve-LS1 S\/D 1.600\u003c\/li\u003e\n\u003cli\u003eOut of Stock Message: Call for Availability\u003c\/li\u003e\n\u003cli\u003eTitle: Manley Valve - Exhaust, Valve-LS1 S\/D 1.600\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\u003eIndustry: Automotive\u003c\/li\u003e\n\u003cli\u003eEngine Valve Quantity: 8\u003c\/li\u003e\n\u003cli\u003eValve Quantity: 8\u003c\/li\u003e\n\u003cli\u003eProp 65 - Short Label: Prop 65 Warning Label.JPG\u003c\/li\u003e\n\u003cli\u003eEngine Type: ICE\u003c\/li\u003e\n\u003cli\u003eMake: Chevrolet\u003c\/li\u003e\n\u003cli\u003eEngine: LS1\u003c\/li\u003e\n\u003cli\u003eProduct Market: Domestic\u003c\/li\u003e\n\u003cli\u003eHead Diameter: 1.600\u003c\/li\u003e\n\u003cli\u003eValve Head Diameter: 1.600\u003c\/li\u003e\n\u003cli\u003eStem Diameter: 0.3136\u003c\/li\u003e\n\u003cli\u003eValve Stem Diameter: 0.3136\u003c\/li\u003e\n\u003cli\u003eO\/A Length: 4.923\u003c\/li\u003e\n\u003cli\u003eInstalled Height: Stock\u003c\/li\u003e\n\u003cli\u003eValve Length: 4.923\u003c\/li\u003e\n\u003cli\u003eValve Tip Length: 0.175\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Manley Performance","offers":[{"title":"Default Title","offer_id":52480989790571,"sku":"MAN11677-8","price":301.08,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/9690\/4998\/files\/public_6d468847-87fb-4fef-993a-6820c0f0fb2d.jpg?v=1778202954","url":"https:\/\/www.raptorracing.com\/products\/manley-chevy-ls-6-head-small-block-severe-duty-pro-flo-exhaust-valves-set-of-8","provider":"Raptor Racing","version":"1.0","type":"link"}