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Manley Performance

Manley Performance

Manley NexTek Valve Springs 221421-16 SPRING-LS-1 .800 LIFT

SKU: MAN221421-16

Valve Springs
Manley NexTek Valve Springs 221421-16 SPRING-LS-1 .800 LIFT
Manley Performance

Manley Performance

Manley NexTek Valve Springs 221421-16 SPRING-LS-1 .800 LIFT

SKU: MAN221421-16

Valve Springs
A$972.15
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

From drag strips to short track and endurance circuits, the Manley NexTek® series is engineered for serious racers. NexTek® springs resist pressure loss and valve-train degradation even in the most demanding race conditions. That means more consistent spring force deep into a run, reduced valve bounce, and improved overall stability for high-RPM performance. Built to outperform and outlast in real-world competition.

Part Type

Engine Valve Spring Kit

Data: v4.2 - Upd: 2026-10-14 10:07:19

Features

  • Manufactured from “super clean” Hi-Tensile Chrome Silicon steel
  • Proprietary multi-step heat treating minimizes load loss
  • Shot-peened to MIL spec for max fatigue life
  • Tightly controlled open-end flatness reduces valve stem side loading
  • Tip thickness designed to eliminate overload breakage

Specifications

Product Attributes - Brand
Manley
Product Attributes - Manufacturer's Part Number
221421-16
Product Attributes - Part Type
Valve Springs
Product Attributes - Product Line
Manley NexTek Valve Springs
Product Attributes - UPC
807298082110
Product Attributes - Valve Spring Style
Standard
Product Attributes - Number of Springs Per Valve
Dual
Product Attributes - Maximum Valve Lift (in.)
0.800 in.
Product Attributes - Retainers Included
No
Product Attributes - Outside Diameter of Outer Spring (in.)
1.324 in.
Product Attributes - Coil Bind Height (in.)
0.900 in.
Product Attributes - Damper Spring Included
No
Product Attributes - Spring Rate (lbs./in.)
435 lbs./in.
Product Attributes - Inside Diameter of Outer Spring (in.)
0.920 in.
Product Attributes - Inside Diameter of Inner Spring (in.)
0.676 in.
Product Attributes - Locks Included
No
Product Attributes - Valve Stem Seals Included
No
Product Attributes - Valve Springs Coated
No
Product Attributes - Remanufactured
No
Product Attributes - Quantity
Sold as a set of 16.
Product Attributes - Notes
Valve springs are fully polished.

Reference Information

Brand Name/s Manley Performance
StreetFX SKU man221421-16
SFX Item ID 4931955
Supplier Item Code 4931955
Manufacturer SKU 221421-16
Manufacturer UPC 807298082110
Alternative References SPRING-LS-1

Compatibility

Application Data
  • MakeCHEVROLET
    Beginning Year1997
    Ending Year2004
    Engine TypeV8
    Engine FamilyChevy small block Gen III/IV (LS-based engines)
    Engine Size5.7L/350
    Installed Height (in.)1.800 in.
    Seat Pressure at Installed Height (lbs.)165 lbs.
    Open Height (in.)(application)1.000
    Open Pressure (lbs.)515 lbs.
  • MakeCHEVROLET
    Beginning Year1999
    Ending Year2014
    Engine TypeV8
    Engine FamilyChevy small block Gen III/IV (LS-based engines)
    Engine Size5.3L/325
    Installed Height (in.)1.800 in.
    Seat Pressure at Installed Height (lbs.)165 lbs.
    Open Height (in.)(application)1.000
    Open Pressure (lbs.)515 lbs.
  • MakeCHEVROLET
    Beginning Year1999
    Ending Year2017
    Engine TypeV8
    Engine FamilyChevy small block Gen III/IV (LS-based engines)
    Engine Size4.8L/294
    Installed Height (in.)1.800 in.
    Seat Pressure at Installed Height (lbs.)165 lbs.
    Open Height (in.)(application)1.000
    Open Pressure (lbs.)515 lbs.
  • MakeCHEVROLET
    Beginning Year1999
    Ending Year2019
    Engine TypeV8
    Engine FamilyChevy small block Gen III/IV (LS-based engines)
    Engine Size6.0L/364
    Installed Height (in.)1.800 in.
    Seat Pressure at Installed Height (lbs.)165 lbs.
    Open Height (in.)(application)1.000
    Open Pressure (lbs.)515 lbs.
  • MakeCHEVROLET
    Beginning Year2006
    Ending Year2015
    Engine TypeV8
    Engine FamilyChevy small block Gen III/IV (LS-based engines)
    Engine Size7.0L/427
    Installed Height (in.)1.800 in.
    Seat Pressure at Installed Height (lbs.)165 lbs.
    Open Height (in.)(application)1.000
    Open Pressure (lbs.)515 lbs.
  • MakeCHEVROLET
    Beginning Year2008
    Ending Year2017
    Engine TypeV8
    Engine FamilyChevy small block Gen III/IV (LS-based engines)
    Engine Size6.2L/376
    Installed Height (in.)1.800 in.
    Seat Pressure at Installed Height (lbs.)165 lbs.
    Open Height (in.)(application)1.000
    Open Pressure (lbs.)515 lbs.

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