I just added an airaid cold air intake and tune to my 13 GT track pack Iam looking to add more power to the car does anyone know which modification would best suit the car for more power?

 

Where are you trying to add more power? Top end or low end? The LTs and x pipe shouldn't rob any torque the way the boss manifold does.

If its top end you power you want and you don't mind losing a little torque, then go with the Boss Manifold. Plan on spinning the motor up to 7600rpm to see the benefits.