Upgrade your 6L80 transmission with Circle D Transmission’s CDT Level 4 Performance 6L80 Parts & Kits, designed for serious builders demanding more power, control, and durability. Our Level 4 kit is engineered for heavy duty applications, ideal for vehicles pushing high horsepower and torque under extreme driving conditions. Whether you’re racing, towing, or simply want to enhance performance, this package gives your transmission the reinforcements it needs.
Included in the kit is a high-quality piston kit, precision-machined for maximum reliability and heat resistance. Combined with our advanced clutch pack and friction materials, this setup ensures firmer shifts and extended service life. The overhaul kit comes complete with all essential seals, gaskets, and components to properly refresh your 6L80 transmission, making it the ideal choice for a full rebuild or major upgrade.
Circle D’s performance 6L80 parts are engineered for maximum boost capacity, allowing your transmission to handle increased power levels without compromising drivability or safety. Whether you’re building for street performance or competitive motorsports, our kits provide the rugged enhancements needed for lasting results. Trust Circle D for precision-built, proven components that raise the bar for performance 6L80 builds.
FREE UPS Ground to the contiguous United States (lower 48) | NO core required for output carrier
Rated up to 1000 RWHP, this kit is engineered for high-powered builds demanding superior transmission durability and reliability. While horsepower ratings are influenced by various factors such as tuning, vehicle weight, power adders, and driving conditions, this kit delivers proven performance for serious applications.
Designed specifically for 6L80 transmissions, this package features high-capacity 45-tooth 4-5-6 clutch plates for improved engagement and reduced clutch failure under heavy load. It also includes CDT’s Billet 4-5-6 clutch hub and intermediate shaft (CDT part number 104680-45), engineered for enhanced control and maximum torque handling. The upgraded 4-5-6 clutch pack provides 50% more surface area than stock, while the 3-5-R clutch pack offers an additional 50% increase in clutch area, boosting both power transfer and longevity.
Built to optimize the performance of GM’s six speed automatic transmission, this kit is ideal for users experiencing slipping, overheating, or clutch-related issues under stress. For complete system integrity, it pairs well with a high-performance torque converter, precision calibration of the transmission control module, and premium transmission fluid. All components are manufactured with a focus on quality, ensuring they can be confidently replaced and trusted in even the most demanding applications.
Includes all 5 Clutch Kits | Detailed Instructions Included | FREE UPS Ground to the contiguous United States (lower 48)
Kit is designed with 45 tooth 4-5-6 clutch plates. This clutch pack provides 50% more surface area than a stock clutch set up. CDT's Billet 4-5-6 clutch hub and intermediate shaft (CDT part number 104680-45-P) is required in order to use this clutch pack. The clutch hub and intermediate shaft are not included in this kit. The 3-5-R clutch pack offers 50% more clutch area than stock.
Detailed Instructions Included |FREE UPS Ground to the contiguous United States (lower 48)
Kit is designed with 45 tooth 4-5-6 clutch plates. CDT's Billet 4-5-6 clutch hub and intermediate shaft (CDT part number 104680-45) is included in this kit. This clutch pack provides 50% more surface area than a stock clutch set up.
Detailed Instructions Included | FREE UPS Ground to the contiguous United States (lower 48)
The required 45-tooth clutch plates are not included with this product and must be purchased separately. This billet shaft is designed specifically to work with 45-tooth clutch plates, ensuring optimal performance and durability in high-powered applications. For best results, pair this clutch kit with high-quality clutch components that match your vehicle’s needs.
FREE UPS Ground to the contiguous United States (lower 48) | NO core required
Engineered for extreme applications, this drop-in component is ideal for nitrous-assisted or heavy vehicles producing over 750 rear-wheel horsepower. It’s manufactured from 4140 HTSR steel, a heat treated, hot rolled alloy known for its exceptional hardness and high strength. The material offers superior mechanical properties, making it well-suited for high-stress automotive environments, particularly in high-horsepower trucks, SUVs, and performance platforms like the CTS-V.
The 4140 HTSR material ensures outstanding wear resistance, especially in driveline systems exposed to intense heat and mechanical stress. Its ability to resist stress fractures and maintain structural integrity under heavy loads makes it ideal for demanding applications where failure is not an option. The high strength and hardness of this steel enhance component longevity and operational reliability in both racing and off-road use cases.
Engineered to meet or exceed OEM specifications, this part is often used in applications involving custom gears, performance bolts, and torque-transmitting assemblies where both resistance to deformation and dimensional stability are critical. With unmatched ability to perform in extreme conditions, it’s the trusted solution for builders and fabricators seeking top-tier metallurgy and precision.
