I was dropping my engine in after a rebuild and the alternator came in contact with a stud, I don’t think it did much besides damage the exterior frame of the alternator, but might have came in contact a little bit with the guts of the alternator. Hard to say. Is my alternator screwed?

 

I cant quite tell from that pic

As alloy is non-magnetic, thats good (dont ever grind steel in an engine bay without wrapping alt and starter in rags and plastic)

If that cracked piece bears any structural force, get another one

If not, you can gamble, if anything is making contact, you will hear it on 1st start

 

Can’t tell if you damaged anything internal. If you run it and it won’t charge the battery, or kills the battery when it sits, you’ll know.

 

I think I'd slacken off the adjuster & turn the pulley by hand, to see if there's any drag (nearly said "resistance" but didn't want to confuse anyone) or unwelcome noises, before firing it up & seeing if it charges..