Stuart, shims under a bearing shell were used to some extent, but it wasn't considered good practice- the desperate last resort, so to speak. There were tapered shims commercially available that were thicker in the center and tapered toward the ends. I don't know if those shims served the intended purpose very well, but they were commonly available in the past. Also, I don't know if the tapered shims came in different thicknesses, but I think they did. Also, I have known aluminum foil to be used under the shell, to take up a thousandth or so of clearance- a last resort again.
Harvester
