1985 K5 blazer starter problems

I’m hoping someone here can tell me what my issue is. I have a 1985 Chevy K5 Blazer, the starter was grinding horribly so I replaced it with a brand new last night and it started perfect. I wake up amd start working on it today and its grinding just as bad as before horrible loud grinding and the whole blazer shakes, I didnt install any of the shims but the feeler gauge was pretty close to perfectly spaced, the bolts are nice and tight so.i know it’s not moving. What’s the deal? The blazer has been sitting for 18 years so could it be a problem with the flywheel instead? Theres not missing teeth and it isn’t locked up as I can spin it by hand. Someone help!

I had one GM, had to replace a bad starter, put the new one on and sounded so bad, pulled it out to take back to the shop, I did not do any shims either. So I put it back in to make a video, making sure it was lined up well. I think I pushed it high as I could before tightening it down, and voila worked fine for 5 years til the vehicle got rear ended.

duplicate thread