+3, not all shops know how to properly balance a set up like yours.I'd bet tire balancing as well. Same thing just happened with me when I lifted mine 3". Is your wheel shaking as well?
Sorry I meant to say if the steering wheel is NOT shaking then the problem lies in the rear endLift kits don not make trucks shake, it is in the wheels and tires, probably the back end is out of balance if the steering wheel is shaking. Re balance and your problems will go away as long as the wheels and tires are not defective. Whee lancing is only as good as the guy doing it. Some guys take their time , some don't, and some just don't know what the f.!.!.!.!.! They are doing