I've "eyeballed it in" at least a dozen times, and never had a problem. It has actually steered pretty darn good on the way to the alignment shop every time.
I think the posts about the idler arm, Pittman arm, and center link may be onto something. The geometry should make it obvious, if something is wrong there. When the car is LEVEL, and the tires/wheels are pointed straight ahead, and the steering box centered in its travel, the center link should be 90 degrees to the longitudinal centerline of the vehicle when viewed from above or below. Similarly, the center link should be parallel to the ground when viewed from the front.
