Rut Row, that doesn't look good!

[Voodoo556]

So the PO of the '70 k20 I picked up last weekend had told me it had a starter issue. He said it needed to be shimmed. Well, it needs to be shimmed alright lol.



There is a chunk of the engine block casting that is missing. I'm assuming it is possible that was caused from him over tightening the bolts. Maybe with an impact or a 3ft cheater bar!
The bolt still tightens but I'm struggling to get the starter dialed in/lined up so it does not bind, screech or drag. I definitely do not want this to be an on going problem.
I'm thinking I might be able to get her shimmed correctly, add a rear support brace to block and then add some blue never seize.

So, what to do.
Options:
Attempt to shim and never seize.
Yank the motor and attempt to "fix"
Yank motor and replace with another short block or complete motor
Yank and replace with big block

Any thoughts fellas?
Thanks