Whenever you lift any vehicle, the suspension geometry is going to change, higher the lift, more radical the change. Sometimes the suspension can be adjusted to compensate, but in the case of our Trackicks, only the toe and camber are adjustable. The castor is fixed and can only be changed by doing something like the widening you mentioned. Or
I think the Calmini and other " hard " lifts, the ones that actually give you re-engineered suspension components like control arms, actually take into account the change in castor necessary to compensate for a higher center of gravity, larger tires, and a fairly unstable short wheelbase, and add castor. Castor is what gives more stability at speed. That and wheelbase. You can get a bit more of both which will add to your highway stability by either buying the " hard " suspension kit, or doing the widening mods.
Or, you can try another alignment shop that knows about modified suspensions. I had to ask around, before I found an old hot rodder who can apperently align just about anything, and he really got mine to handle nice. But it sure ain't no longwheelbase pickup, especially in the wind.
Did they ( alignment shop ) Check your steering box and linkage for the correct amount of play?