the ideal thing would be to have a rack narrowed to move the inner pivot point of the tierods closer together. but with the dakota rack , if its mounted in the right place you should have only a small amount of bump steer and you wouldnt even notice it driving the car if its right.
i am guessing you need to either space the rack up higher or space the tierod ends down on the spindle. one question for you is ,did you mount the tierod to the top or bottom of the spindle arm? if its mounted to the top you will have really bad bump steer. if its mounted to the bottom it may need spaced down. are you using a factory tierod end or a aftermarked type rod end?
i normally use a 5/8 rod end and drill out the spindle for a 5/8 grade bolt and use spacers to set the bump steer. you should be able to get it to work well with out narrowing the rack.

are you using the parts on a daytona or rampage?