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Rocker Arm Lock Nut – Honda GX390 / Predator 420 / Wildcat 460 (Big Block Clones)
188F-13204-A GX390/420 Clone Rocker Arm Lock Nut
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Rocker Arm Lock Nut – Honda GX390 / Predator 420 / Wildcat 460 (Big Block Clones)

Part Number: 188F-13204-A
On sale: $0.99 $0.21
Phone Order Price:$0.23
You Save:$0.02(9%)
Rocker Arm Lock Nut – GX390 / Predator 420 / Wildcat 460 (Wedge Head)
Availability: In Stock.

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Description

Rocker Arm Lock Nut – Honda GX390 / Predator 420 / Wildcat 460 (Big Block Clones)


This steel Rocker Arm Lock Nut is used to secure the adjuster nut that sets valve lash in Wedge (Non-Hemi) cylinder heads on Honda GX390 and Big Block Clone engines, including Predator 420 and Wildcat 460 models.


It prevents lash settings from loosening due to vibration or high-RPM operation—critical for maintaining consistent engine performance in racing, pulling, or heavy-duty applications.


Product Features:

  • Thread Size: M6 x 0.75 (matches standard rocker arm studs and adjusters)
  • Material: Durable steel construction
  • Torque Spec: 7 ft-lbs (use 10mm socket)
  • Application: Secures rocker arm lash adjuster in non-hemi heads
  • Compatibility: Fits most GX390, Predator 420, Wildcat 460, and other Big Block Clones using stud-mounted rocker arms


Fitment Note:

  • Not for Hemi Heads – Does not fit shaft-mounted rocker systems
  • For Wedge (Non-Hemi) heads only with M6 x 0.75 lash adjusters


Ideal For:

  • Valve lash adjustments
  • High-vibration or racing environments
  • Performance engine builds and maintenance

FAQ

Q1: What engines is this lock nut compatible with?

A: It fits most Wedge (Non-Hemi) cylinder heads on Honda GX390, Predator 420, Wildcat 460, and other Big Block Clone engines.


Q2: What is the thread size of the lock nut?

A: The thread size is M6 x 0.75, matching the typical rocker adjuster thread in non-hemi engines.


Q3: What torque spec should be used when tightening this nut?

A: Torque to 7 ft-lbs using a 10mm socket.


Q4: Can this lock nut be used on Hemi-style heads?

A: No. Hemi-style heads use shaft-mounted rocker arms, which do not require this type of lock nut.


Q5: Why is a lock nut important in the valve train?

A: The lock nut keeps the valve lash adjuster securely in place, preventing unwanted changes in lash due to vibration or high RPM operation. It's critical for consistent valve timing and performance.

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