Manley Chevrolet LS1intake Valve Kit - 2.055in Head Dia. 4.874in O/A Length, 0.3133in Stem - 11680H-8

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.

Features

• Proven fatigue strength for extreme performance
• Chrome stems and hard tips enhance durability
• Exotic alloys for superior tensile strength, reliability, and longevity
• Swirl polishing and machined faces improved airflow/optimized efficiency

Specs

• Head Diameter: 2.055 in
• Stem Diameter: .3133 in
• O/A : 4.874
• Hollow Stem
• Manley Valve
• Intake, Valve-LS1 P/F 2.055 HOLLOW
• Margin Width: 0.050
• Seat Width: 0.095
• Top of Head: 7 Degree Dish
• Valve Head Shape: 7 Degree Dish
• Underhead Angle: Pro Flo: 12.00
• Underhead Radius: 3/8
• Weight: 95
• Cylinder Head: LS6 Cylinder Head
• Valve Series: Severe Duty? Series
• Valve Sub-Series: Pro Flo
• Valve Material: Stainless Steel
• Valve Type: Intake
• Product Type: Engine Intake Valve Kit
• Valve Quantity: 8
• Engine Valve Quantity: 8
• Industry: Automotive
• Out of Stock Message: Call for Availability
• Title: Manley Valve - Intake, Valve-LS1 P/F 2.055 HOLLOW
• Prop 65 Yes/No: Yes