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Manley Chevrolet Big Block 2.300 Head, .3415 Stem, .350 Longer Severe Duty Valves (Set of 8)

SKU: MAN11878-8

Valves

MAN Severe Duty Valves...

Manley Chevrolet Big Block 2.300 Head, .3415 Stem, .350 Longer Severe Duty Valves (Set of 8)

SKU: MAN11878-8

Valves

MAN Severe Duty Valves...

A$611.16
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 Intake Valve

Data: v4.2 - Upd: 2026-10-21 02:16:27

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
11878-8
Product Attributes - Part Type
Valves
Product Attributes - Product Line
Manley Severe Duty Series Stainless Steel Valves
Product Attributes - UPC
807298054629
Product Attributes - Valve Position
Intake
Product Attributes - Intake Valve Head Diameter (in.)
2.300 in.
Product Attributes - Intake Valve Head Diameter (mm)
58.420mm
Product Attributes - Intake Valve Stem Diameter (in.)
0.341 in.
Product Attributes - Intake Valve Stem Diameter (mm)
8.66mm
Product Attributes - Intake Overall Valve Length (in.)
5.610 in.
Product Attributes - Intake Overall Valve Length (mm)
142.494mm
Product Attributes - Undercut Stem
No
Product Attributes - Swirl-Polished
Yes
Product Attributes - Valve Tip Length (in.)
0.250 in.
Product Attributes - Valve Tip Length (mm)
6.350mm
Product Attributes - Valve Material
XH-428 stainless steel
Product Attributes - Lock Groove Quantity
1-groove
Product Attributes - Lock Groove Style
Conventional
Product Attributes - Approximate Weight (g)
149
Product Attributes - Valve Head Style
7 degree dish
Product Attributes - Valve Seat Width (in.)
0.100 in.
Product Attributes - Quantity
Sold as a set of 8.

Reference Information

Brand Name/s Manley Performance
StreetFX SKU man11878-8
SFX Item ID 4060964
Supplier Item Code 4060964
Manufacturer SKU 11878-8
Manufacturer UPC 807298054629

Compatibility

Application Data
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1965
    Ending Year1970
    Engine TypeV8
    Engine Size6.5L/396
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.350 in. over
    Cylinder Head TypeStock configuration
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1966
    Ending Year1969
    Engine TypeV8
    Engine Size7.0L/427
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.350 in. over
    Cylinder Head TypeStock configuration
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1970
    Ending Year1972
    Engine TypeV8
    Engine Size6.6L/402
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.350 in. over
    Cylinder Head TypeStock configuration
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1970
    Ending Year1990
    Engine TypeV8
    Engine Size7.4L/454
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.350 in. over
    Cylinder Head TypeStock configuration
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1991
    Ending Year1995
    Engine TypeV8
    Engine Size7.4L/454
    Engine FamilyChevy big block Gen V
    Valve Installed Length0.350 in. over
    Cylinder Head TypeStock configuration
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1996
    Ending Year2000
    Engine TypeV8
    Engine Size7.4L/454
    Engine FamilyChevy big block Gen VI
    Valve Installed Length0.350 in. over
    Cylinder Head TypeStock configuration

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