Starter Issues

[HeloCrewChief]

I recently picked up a 1969 C10. The owner told me it needed a starter. I installed a new starter and it started up fine the first time. As soon as I shut it off and went to start it again I heard the most horrible clanking/grinding noise. I went back to the auto parts store and tried a different starter. Same thing happened. I tried shimming the starter in all configurations and it made no difference. I also replaced the alternator,battery and battery cables. The truck will eventually start if you crank it over a few times but, it makes a horrible noise and shakes the whole starter bad. The flywheel looks good. Is it possible it is bent? Any ideas on what it could be