American Powertrain Tremec TKX manual transmissions put the power to the pavement with unmatched durability and versatility. Tremec has normally sourced their aftermarket transmissions from the OE side, such as the Magnum T-56 and the T-5, but this new design is made from the ground up as a strictly aftermarket transmission. Designed to fit classic muscle cars and customs, the TKX has a tighter, more streamlined case.

TKXs have 600 lbs.-ft. of torque capacity and are capable of engines speeds of 8,000 rpm with shifts at 7,500 rpm. They're available with multiple gear ratio configurations and are designed for multiple applications with three shifter locations. The compact design provides clearance in most transmission tunnels without floor modifications. Case strength has increased from previous models with the new 3-piece aluminum housing. Gaskets at all flanges simplifies installation and eliminates fluid leaks.

The TKX features multi-cone synchronizers and synchronizer rings made of sintered bronze and carbon for superior shifts. All gears are supported by caged needle bearings to reduce end play. Gears and shafts are made from ASTM 4615 grade steel and provide increased torque carrying capacity. Tremec TKX manual transmissions have 31-spline output shafts for added strength, built-in reverse light switches, and cruise control safety switches. The TKX also has separate GM and Ford case patterns and input configurations—with integrated GM and Ford transmission mount patterns.