The general rule of thumb is .020 per inch up or down. Bob, I'm not sure the gauge in the picture will give you the answers you need. As the wheel moves through its motion it will move in and out because your control arms move through a natural arch. To measure how much the toe changes, you would need to place your dial indicator in the front(as you have it) and one in the rear. As the tire moves, measure the change front and rear then subtract one from the other. That is your bump steer number. Here is my tool for measuring bump steer. Even if the front gauge and the rear gauge move out .090, but move the same amount, you have 0 bump steer.
