Greg chose to replace his ’Stang’s tired stock transmission with Tremec’s TKO 500 (PN TCET-4615). The replacement five-speed features a 10-spline input shaft, 31-spline output shaft, and a close-ratio gearset (3.27 First gear; the stocker’s First is 3.35). While the TKO 500 supports 500 lb-ft of torque, we’re estimating the Clevor’s torque will be right in that range or a tad higher, especially when the juice is flowing. As a precautionary measure, we’re swapping the 10-spline input with a 26-spline shaft assembly from AMP Performance (PN 2606412). TKO 500s are available with a 26-spline input already installed (PN TCET-5201). Unfortunately, however, none were available during our time of need, which is why we’re performing the upgrade. While 26-spline input shafts typically are found in Tremec’s TKO 600 trannys and have 2.87 firsts, AMP set up our replacement with the same 3.27 first gear that’s in the 500.