Adding Power Steering on 68 Questions

[chevykevy]

I have read a few threads concering the addition of power steering to 67 and 68 Chevys without the dimple in the frame to allow the radius of a power gear box to fit . Some folks say that if I space out the gear box with bushing material or washers, 1/2 inch, that it will work just fine. Others however, say that I will cause a bad case of bump-steer. I thought that as long as I adjusted the pitman arm the necessary number of teeth to make up for the the 1/2 to the left movement, as well as set the toe with the collars on the inner and outer tie rods, that there wouldn't be a problem. Does anyone have any suggestions or experience with the problem, to shed light on it for me, before I invest time and money in the project?
Thanks