[LS short box]

As I understand you don't need to take out all of the torque management out. Per the tune it can be adjusted to leave certain percentage in.
If you still have the stock tune in the ecm the trans will up shift sooner because GM wants the vehicle to go up into a higher gear as soon as possible for better gas mileage. A tuner can adjust the shift points to what ever makes you happy. Because there are bunch of 40 mph streets I use quite often I have the tuner delay the lock up of the torque converter until 45 mph. Helps prevent lugging the engine. All the tuner needs is your tire diameter, trans type and gear ratio to do the calculation.