Cosworth Ultra-High RPM Dual Valve Spring / Retainer Set | Multiple 4G63 Fitments (KK3813)

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  • Regular price $916.00

Ultra-High RPM Dual Valve Spring / Retainer Set by Cosworth

We specialize in engineering engine components optimized for high performance engines with the highest quality and attention to detail possible. Our ultra racing valve spring kits are designed to maintain precise valve control, even in the most extreme conditions. By manufacturing our springs with chamfered ends from the highest quality chrome silicone steel and putting them through a two step heat treatment and stress relief process, we ensure precision and dependability.

Included with this kit are valve springs, lightweight titanium retainers and hardened steel spring seats.

Replacement Components
COS1 PR7505, Valve Keeper


  • Type: Spring / Retainer Set
  • Head Alteration Required: No
  • Inner Valve Spring: No
  • Location: Intake and Exhaust
  • Machining Required: No
  • Retainers: Titanium
  • Mfgr. Warranty: No Warranty


  • 1990-98 Eagle Talon TSi
  • 1990-99 Mitsubishi Eclipse GST
  • 1990-99 Mitsubishi Eclipse GSX
  • 1996-99 Mitsubishi Eclipse Spyder GST
  • 2003-06 Mitsubishi Lancer Evolution
  • 2005-06 Mitsubishi Lancer Evolution MR
  • 2005-06 Mitsubishi Lancer Evolution RS
  • 2006 Mitsubishi Lancer Evolution SE

What's In The Box?

  • Spring / Retainer Set