Fits Like a Glove in Older Rides

Originally developed by GM as an upgrade to the 4L60E, the 4L65E was designed to meet the rising demands of performance vehicles. Though it looks nearly identical on the outside, it features internal enhancements—including a hardened input shaft, stronger sun shell, and a five-pinion rear planetary gear set. These enhancements make the 4L65E ideal for street performance, towing, or track use—easily handling more torque and heat than its predecessor.

Thanks to its two-piece case design and compact size, the 4L65E fits easily into most older vehicles without major modifications to the transmission tunnel. It’s a go-to option for hot rodders, classic car restorers, and custom builders alike.

Ideal for LS Engine Swaps

The 4L65E features a 7-bolt LS bellhousing pattern and a 13-pin main harness connector, making it highly compatible with modern GM engines and standalone transmission controllers. Whether your build is fuel injected or carbureted, Gearstar will configure your transmission to match your setup—including popular systems like Holley Sniper or Edelbrock Pro-Flo.

This level of adaptability has made the 4L65E one of the most popular transmissions for LS swap applications, especially for builds staying under the 650-horsepower mark.

Mopar-Compatible Transmission Option

For Mopar enthusiasts looking to modernize their drivetrain, Gearstar offers a version of the 4L60E/4L65E with a Mopar-specific bellhousing. Whether you’re running a Small Block, Big Block, or Gen III HEMI, this package includes a specially designed torque converter and requires a standalone controller—making it one of the few high-performance GM automatic transmissions available for Mopar engine applications.

Custom-Built, Not Mass-Produced

At Gearstar, every 4L65E is hand-built from start to finish by a single master technician. This hands-on approach ensures complete quality control and unmatched attention to detail. There are no assembly lines—just one expert dedicated to your build from the first bolt to final test.

Before shipping, each unit is dyno-tested for the equivalent of 100 miles. This rigorous process guarantees the transmission is performing flawlessly before it ever leaves the shop—saving you time and hassle during installation.

Perfectly Paired Torque Converter Included

Every Gearstar 4L65E package includes a custom torque converter, engineered specifically for your vehicle’s power level, application, and performance goals. Since acquiring Yank Performance Converters in 2022, Gearstar has brought converter manufacturing entirely in-house, ensuring seamless integration across the engine, transmission, and drivetrain.

Designed to Perform—Built to Last

Gearstar offers several performance levels for both 2WD and 4×4 applications. These range from Level II units rated for up to 400 horsepower to Level IV packages capable of handling 650 horsepower in 2WD or 600 in 4×4 configurations.