My 98 X-90 has a Calmini 2" lift on it and larger than stock tires (Street tires). If I hang a corner at high speeds turning right it is stable, drifts evenly and is very confident handling. But, turning left in the same situation it feels like the front end wants to push out and feels unstable.
I'd assume it was stable before the 2" lift was added. The things I'd be looking at is that the lift is installed properly, and the tires. (The lift kit on the Bronco caused similar handling.)
You could try swapping the front wheels (temporarily) and see if that helps. If it's not a symetric tread, that can cause a prob similar to this. (i.e. a directional tread installed backwards.) Better, if you have some good street tires on a rig, try them out. That will focus you on whether it's tires or something else.
It could be something odd. The oddest (non-zuki) I ever saw was a broken motor mount... and on another a rear leaf spring's shackles loose. Did they do a 4-wheel alignment? If the rear end isn't square to the front, it can cause odd steering. (Not much you can do about this, unless it's something worn.)
...just a thought...