1987 Chevy 350, starter issues

I put a rebuilt starter in, no shims. It started great for 2 months. Now every other time it hits the flywheel. I put an .030 shim in and it still hits once in a while.

You can try adding another shim, I've seen them shimmed as much as .060. Also look at the condition of your starter drive teeth and those on the flywheel, you might have a bad section with a few chewed up teeth.

Also if possible, make sure that the starter housing is correct for your car, many GM starters look almost the same, but have subtle differences that could cause a mis-match.

Bob