Start messing with the geometry and weird things happen, but the tires HAVE to be good 1st. Take em down and have balanced checked.
At least jack it up in driveway and see if you got play in hubs with the tires on.
I suspect your "lift" was done without replacing any stock suspension parts and is why it may look ok, but is at upper end of limits thereby yankin ya around easier..but its hard to tell from here.. good luck | 
