Circle D GM 258mm Pro Series 6L80E Torque Converter

Circle D Specialties GM 258mm Pro Series 6L80E Torque Converter

The Circle D Specialties GM 258mm Pro Series 6L80E Torque Converter is a highly versatile, high-performance upgrade for enthusiasts running a 6L80 transmission in their modified GM vehicle. The 258mm (10 1/4-inch) diameter offers a perfect middle ground—significantly reducing rotational mass for rapid throttle response and quick acceleration off the line, while maintaining slightly more surface area than our 245mm option for excellent streetability and efficient torque transfer.

Engineered to deliver massive value and handle serious power, this Pro Series converter features a rigid billet steel front cover and billet piston to completely eliminate flexing and ballooning under load. Crucially, it utilizes a Triple Disk Lockup clutch assembly, providing unmatched holding capacity for wide-open throttle (WOT) lock-up tuning on modern 6-speed applications. Internally, a flanged impeller hub ensures superior anti-flex durability, while the assemblies are fully furnace brazed with a hand TIG welded turbine hub. For builders planning to use aggressive power adders, an optional Heavy Duty Upgrade is available, adding essential additional balloon plating on the impeller along with heavy-duty welding.

Key Features & Upgrades

• Designed specifically for GM 6L80 / 6L80E transmissions
• 258mm (10 1/4") diameter delivers a superior balance of rapid engine response and streetable torque holding
• Triple Disk Lockup for extreme holding capacity during wide-open throttle (WOT) shifts
• Rigid one-piece billet front cover and billet piston prevent flexing and ballooning
• Optional Heavy Duty Upgrade: Adds additional impeller balloon plating and heavy-duty welding for extreme applications
• Flanged impeller hub engineered for superior anti-flex durability
• Furnace brazed internals with hand TIG welded turbine hub
• Heavy-duty Torrington bearings for smooth, reliable operation
• Hand-assembled to exacting tolerances for dominant track performance

Specifications

• Application: High-Performance Street/Strip Torque Converter
• Transmission Compatibility: GM 6L80 / 6L80E
• Converter Diameter: 258mm (10 1/4")
• Construction: Billet Front Cover & Piston, Furnace Brazed, Hand TIG Welded Turbine Hub
• Lockup Type: Triple Disk
• Bearings: Torrington Bearings
• Options: Multiple Stall Speeds (2800 up to 3700 RPM), Sprag Options, and Heavy Duty Upgrade available

Notes

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