1958-1964 GM B-Body TREMEC TKX, Magnum, & A41 4L60E Transmission Kits

Modernize the driveability of your 1958-1964 GM B-Body with our PerfectFit™ Transmission Kits. Specifically engineered for the iconic X-frame Chevrolet Impala, Bel Air, Biscayne, and El Camino, we offer the industry’s best overdrive solutions. Choose from the streamlined TKX 5-Speed, the high-torque Magnum 6-Speed, or our smooth-shifting A41 4L60E Electronic Automatic.

These kits are designed to provide a seamless fit into your classic 1958-1964 chassis, delivering reduced cruising RPMs and a transformed driving experience. Each system arrives as a total solution, featuring all the high-quality components required for a professional, high-performance installation that respects the unique geometry of your vintage B-Body.