I don't have them, but I think they will do quite the oppisite, your going to feel the vibrations more because there won't be any rubber to absorb any vibrations.
I have them. They added no vibration whatsoever. I also have a flaming river solid steering shaft, which also added no vibration. The main purpose of the aluminum bushings is to move the steering rack closer to the K member. The other purpose is to ditch the stock rubber bushings which allow the rack to move.