280mm LU (4L60-E) “VJCX”, 300mm (4L60-E), 4L60-E (300mm), Single-Plate Performance Converter (Mounting Ring)

300mm Performance Converter Mounting Ring Kit
Part No. GM-RK-13

View Instructions

Sonnax 300mm performance converter mounting ring kit GM-RK-13 allows an early GM 245mm lockup core to be adapted for use in 4L60-E applications that originally came with 300mm lockup torque converters. When used along with Sonnax turbine hub GM-HTCM-57, this kit allows a late 245mm core to be adapted for use in GM 300mm lockup applications.

The Sonnax kit is designed to work with the early GM 245mm piston/damper assemblies. The 4L60-E torque converter clutch controls are of the EC3 variety. Due to this, use only woven carbon or High Thermal Engaging (HTE) friction linings.

High torque applications can overpower the torque capacity of stock GM 245mm single disc clutch and damper assemblies. The ability of this single disc clutch to handle a specific torque load is dependent on many factors, including the amount of input torque and the strategy that is used in applying the torque converter clutch. Sonnax does not guarantee that the capability of the 245mm damper assembly will be adequate in all applications.

  • Impeller Hub
  • Turbine Hub
  • Pilot
  • Spacers (3)
  • Mounting Ring
  • Bolts (3)
  • Unit Size: 10"
  • Core: GM 245mm
  • Dampered: Yes
  • Lockup: Single-Plate
  • Transmission Unit: 4L60-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 (300mm), Single-Plate Performance Converter (Mounting Ring) 300mm Performance Converter Mounting Ring Kit GM-RK-13

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!