Circle D GM 258mm Pro Series 4L60 LS Torque Converter

Circle D Specialties GM 258mm Pro Series 4L60 LS Torque Converter

The Circle D Specialties GM 258mm Pro Series 4L60 LS Torque Converter delivers exceptional versatility and holding power for highly modified GM vehicles equipped with a 4L60 transmission and LS engine. Stepping down to a 258mm (10 1/4") diameter significantly reduces rotational mass compared to a factory 300mm converter. This allows for rapid engine response and quick spooling while providing a slightly tighter street feel than our most compact 245mm race options.

Built to handle aggressive track abuse, this Pro Series converter features a completely rigid billet front cover and billet piston to eliminate flexing and ballooning under load. Internally, it is equipped with a flanged impeller hub for superior anti-flex durability and a deep groove ball bearing design for longer clutch life. If your build utilizes heavy nitrous or forced induction, be sure to select the optional Heavy Duty Upgrade, which adds essential additional impeller balloon plating and heavy-duty welding to ensure absolute reliability under extreme boost and torque loads.

Key Features & Upgrades

• Designed for GM 4L60 transmissions with LS engines
• 258mm (10 1/4") diameter delivers rapid throttle response with excellent streetability
• Rigid billet front cover and billet piston prevent flexing and ballooning
• Optional Heavy Duty Upgrade: Adds additional impeller balloon plating and heavy-duty welding for high-boost/nitrous applications
• Deep groove ball bearing design significantly extends clutch life
• Flanged impeller hub engineered for anti-flex durability
• Furnace brazed internals with hand TIG welded turbine hub
• Hand-assembled to exacting tolerances for reliable, dominant track performance

Specifications

• Application: High-Performance Street/Strip Torque Converter
• Transmission Compatibility: GM 4L60
• Engine Compatibility: LS
• Converter Diameter: 258mm (10 1/4")
• Construction: Billet Front Cover, Furnace Brazed, Hand TIG Welded Turbine Hub
• Bearings: Heavy-Duty Torrington Bearings & Deep Groove Ball Bearing
• Options: Multiple Stall Speeds (2800 up to 3700 RPM) and Heavy Duty Upgrade available

Notes

• Custom manufactured product built to your exact specifications.
• Estimated lead time: 3-4 weeks.