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Manley Severe Duty Series Stainless Steel Valves 11561-8 Valves, Exhaust, Steel, 1.940 in. Diameter, .371 in. Stem, 5.374 in. Length, Chevy, Set of 8

SKU: MAN11561-8

Valves

Manley Severe Duty Series Stainless Steel Valves 11561-8 Valves, Exhaust, Steel, 1.940 in. Diameter, .371 in. Stem, 5.374 in. Length, Chevy, Set of 8

SKU: MAN11561-8

Valves
A$591.71
Special Order. Contact for ETA. This item is out of stock in our warehouse and partner distribution centres. In some cases, this may be due to not having live inventory feeds available for all suppliers. Please contact us before ordering if you need to meet a specific deadline.
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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.

Part Type

Engine Exhaust Valve

Data: v4.2 - Upd: 2026-10-14 10:08:49

Features

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

Specifications

Product Attributes - Brand
Manley
Product Attributes - Manufacturer's Part Number
11561-8
Product Attributes - Part Type
Valves
Product Attributes - Product Line
Manley Severe Duty Series Stainless Steel Valves
Product Attributes - UPC
807298050201
Product Attributes - Valve Position
Exhaust
Product Attributes - Exhaust Valve Head Diameter (in.)
1.940 in.
Product Attributes - Exhaust Valve Head Diameter (mm)
49.276mm
Product Attributes - Exhaust Valve Stem Diameter (in.)
0.371 in.
Product Attributes - Exhaust Valve Stem Diameter (mm)
9.42mm
Product Attributes - Exhaust Overall Valve Length (in.)
5.374 in.
Product Attributes - Exhaust Overall Valve Length (mm)
136.410mm
Product Attributes - Undercut Stem
Yes
Product Attributes - Swirl-Polished
Yes
Product Attributes - Valve Tip Length (in.)
0.220 in.
Product Attributes - Valve Tip Length (mm)
5.588mm
Product Attributes - Valve Material
NK-844 stainless steel
Product Attributes - Lock Groove Quantity
1-groove
Product Attributes - Lock Groove Style
Conventional
Product Attributes - Approximate Weight (g)
139
Product Attributes - Valve Head Style
7 degree dish
Product Attributes - Valve Seat Width (in.)
0.080 in.
Product Attributes - Quantity
Sold as a set of 8.

Reference Information

Brand Name/s Manley Performance
StreetFX SKU man11561-8
SFX Item ID 4930451
Supplier Item Code 4930451
Manufacturer SKU 11561-8
Manufacturer UPC 807298050201

Compatibility

Application Data
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1966
    Ending Year1969
    Engine TypeV8
    Engine Size7.0L/427
    Engine FamilyChevy big block Mark IV
    Valve Installed LengthStock
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1966
    Ending Year1970
    Engine TypeV8
    Engine Size6.5L/396
    Engine FamilyChevy big block Mark IV
    Valve Installed LengthStock
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1970
    Ending Year1972
    Engine TypeV8
    Engine Size6.6L/402
    Engine FamilyChevy big block Mark IV
    Valve Installed LengthStock
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1970
    Ending Year1990
    Engine TypeV8
    Engine Size7.4L/454
    Engine FamilyChevy big block Mark IV
    Valve Installed LengthStock
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1991
    Ending Year1995
    Engine TypeV8
    Engine Size7.4L/454
    Engine FamilyChevy big block Gen V
    Valve Installed LengthStock
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1996
    Ending Year2000
    Engine TypeV8
    Engine Size7.4L/454
    Engine FamilyChevy big block Gen VI
    Valve Installed LengthStock

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