I recently had a quick ratio steering rack (15:1) installed on my 89, and the bump steer has become more noticable. Would a bump steer kit solve the problem?
Bump steer is related to the suspension and steering geometry, nether of which changed, so a bump steer kit won't do anything. Those are for lowered cars.
In a previous car I did something similar and there was no difference at all. Your car shouldn't have much bump steer anyway...