if at the 'big end' you are hanging on pretty hard, then you're camber is effecting the tracking (at the least). you'll want to run the same toe-in (-.5degrees) as stock up front. and i'd suggest (-1 or -.5 degrees toe in the rear).
Then take your caster and increase it as much as possible. this will give you a softer and more controllable steering wheel at speed, all be it vague and less responsive for turns (racing/roadcourse type turns)