Power Performance is proud to offer transmission tuning for your Allison 5 and 6 speed equipped Duramax! This transmission tuning will allow for the torque converter to be applied in second gear (while in tow haul-request otherwise if you want it for more than just tow haul). This is good for knocking off close to at least .05 off your track times! No more lock up boxes needed, its all handled by a simple flash! Transmission tuning is extremely beneficial to trucks running bigger than stock turbo applications, it is really nice to stay on top of the charger at part throttle and not bog down in between shifts. Please note that you must currently be using tuning from Kory Willis of Power Performance Enterprise, Inc. in order to utilize this upgrade.