TKX 5-Speed Transmission GM 26-Spline

The TKX 5-Speed Transmission GM 26-Spline represents a modern overdrive solution for classic and restomod General Motors vehicles seeking improved fuel economy and highway cruising capability. This transmission upgrade addresses the limitations of original equipment three- and four-speed gearboxes, delivering the efficiency and performance standards expected in contemporary automotive builds. Whether you're restoring a muscle car, building a street rod, or upgrading a vintage truck, the TKX 5-speed transmission provides the versatility needed to balance power delivery with real-world drivability across a broad RPM band.

Engineered specifically for GM engine platforms with 26-spline output shafts, this transmission incorporates modern synchronizer technology and internal gear ratios optimized for both acceleration and highway efficiency. The five-speed design—including a true overdrive fifth gear—reduces engine RPM at cruising speeds, lowering heat generation and extending drivetrain longevity. At approximately 65 pounds, the TKX transmission is competitively lightweight while maintaining robust internal construction capable of handling realistic street torque loads and daily driver duty. The compact footprint, measuring 18 x 14 x 34 inches, facilitates installation in applications where space constraints would reject heavier or bulkier alternatives.

Builders and restorers with early-generation GM vehicles—particularly those equipped with small-block or big-block Chevy engines—will find the TKX 5-Speed Transmission GM 26-Spline an ideal bolt-in upgrade requiring standard transmission tunnel modifications and proper driveshaft length adaptation. Installation demands attention to bellhousing alignment, shifter linkage configuration, and electronic speedometer calibration if original mechanical instrumentation is retained. This transmission supports both street and moderate performance applications, making it suitable for weekend cruisers, restorations prioritizing usability, and daily-driven classics requiring contemporary shift quality and efficiency standards.