Nope, transmission is PHYSICALLY identical to our 5-speed's. Only change is the addition of a bypass tube in the valve body to allow actuation of "6th" gear (which in reality is just a different combination of the same 3 planetary gear sets and clutchpacks) and different TCM programming. Reverse, and 1st thru 5th gears are exactly the same...6th gear is just a "double over-drive", designed to drop RPM's when cruising unloaded. I doubt it'd be useful towing tho, its geared too low. I think Tow/Haul might lockout 6th gear. In that case, it would be identical to driving one of our 5-speed M74 Allison's.
----Ben