Here is an update:
Tried shimming with .015, .030, .045, .60 with no change in sound. Jumped up to .090 and got some clunking sounds when cranking, figured I went too far. Backed down to .075 and got the original sound again. This morning I tried .084 and got a very high pitch sound when cranking, the FSM says this means you have to remove shims. Since shimming does not seem to change this sound unless too much thickness is added, I am fairly convinced the sound is from the starter itself and not due to shimming. Finally left in a .060 shim just to make sure the clearance is not too tight.
Probably the rebuild is not as good as it could be. What would you recommend, run it as is as long as it works, take it back to the rebuilder, or buy another one and see if it is any better?
Thanks