280mm LU (4L60-E) “VJCX”, 300mm (4L60-E), 4L60-E, 4L65-E, 4L75-E (300mm), Multi-Plate Performance Converter

300mm Performance Converter Kit
Part No. GM-RK-408WC

Street/Strip applications only. For use with GM 258mm early-style stators only.

View Instructions

A performance torque converter is highly specialized based on the performance characteristics of the specific vehicle. And Sonnax has several levels of kits to ensure the best combination of performance and value for each application.

Sonnax 300mm performance converter kit GM-RK-408WC for GM 4L60-E, 4L65-E, 4L75-E (300mm) applications, now available with woven carbon clutch plates, delivers the performance characteristics of a high-stall with maximum lockup capacity. Sonnax performance converter kits ensure fast, easy assembly with predictable tuning adjustments.

Sonnax offers the most comprehensive range — and growing number — of performance converter kits for anyone building a GM 4L60-E, 4L65-E, 4L75-E (300mm). Other kits that utilize GM 245mm or 265mm core are available.

  • Build in a variety of stall speeds
  • Fast, easy assembly with predictable tuning adjustments
  • Fits 10.750", 11.062" and 11.500" flexplate bolt patterns
  • Chromoly steel turbine and impeller hubs for strength and durability
  • Fully-machined forged front cover and damperless piston add strength and durability
  • Sprag cartridge delivers more than twice the holding capacity of OE
  • Weld-on pilot adapts to many applications

Includes Sonnax base kit [GM-RK-20MWC].

  • Impeller Hub
  • Sprag Cartridge
  • Rivets (20)
  • Turbine Hub
  • Pilot
  • Front Cover
  • Washer Vespel®
  • O-Ring Fluorocarbon
  • Seal PTFE
  • Damperless Piston
  • Thrust Bearing Turbine-side
  • Thrust Bearing Impeller-side
  • Clutch Plate with Internal Splines, Woven Carbon Frictions
  • Clutch Plate with External Splines, Woven Carbon Friction
  • Dampered: No
  • Lockup: Multi-Plate
  • Unit Size: 300mm
  • Core: GM 258mm
  • Clutch Material: Woven Carbon
  • Transmission Unit: 4L60-E, 4L65-E, 4L75-E
  • Turbine Hub Input Spline Count: 30

Where to Buy

  • Existing Customers: Contact your sales representative.
  • New Customers: Fill out the form and a sales representative will contact you.
  • 280mm LU (4L60-E) “VJCX”, 300mm (4L60-E), 4L60-E, 4L65-E, 4L75-E (300mm), Multi-Plate Performance Converter 300mm Performance Converter Kit GM-RK-408WC

Sonnax Performance Converter Kits

Engineered to Deliver Builds that Last

Designed from the ground up to outperform OE and other aftermarket components, Sonnax has you covered with a full line of performance converter kits for gas and diesel vehicles. Offering the widest variety of options in the aftermarket, these innovative kits deliver customized performance and value.

  • Small/Large Diameter
  • Single-Plate/Multi-Plate/Non-Lockup
  • Dampered/Damperless


Choose the right kit for your rebuild!