Originally Posted by MikeR

I suggest 5-6mm of spacers (depends on your servo size) and the alloy horn. You want the turnbuckles perfectly level to eliminate the bump steer. Grind under the arms if they rub the turnbuckle when the suspension is compressed and the wheels are turned.
Yes, you can slide the servo forward or back as well to adjust ackerman. Bonus points for that

Here is Hayato Matsuzaki's car with the same set up;