I went through the same thing with my '99 when I did a 3" level kit to the front. The key was changing the trac bar. I wasn't able to find one (early '99) so I cut and extended mine to solve the problem. Hope this helps.
Drop the pitman arm. Bump steer is caused when the steering linkage and the is not close to level. If it is at an angle, every time you hit a bump you move the linkage resulting in a steering change.