It is not the travel of the steering box but the overall travel of the steering. The asisest way to find that value (I haven't done it in years) is to put the car on jackstands and put a plumbbob on the centerlink. Turn the wheel to one side tit locks and make a mark on the floor where the plumbbob is...then turn the wheel all the way the other direction until lock and mark the floor again. The distance between these two marks is the total travel necessary to keep from losing turning radius. Good luck finding a rack with this amount of travel becuase I don't think it exists.