Possibly find a really good other used engine. The cost of doing a reasonably good rebuild is not in the chev 350 engine cost range.

You perhaps are in the best area of north America to find one. For example I think pistons are over five hundred each if needed. The non turbo engines pistons are a lot cheaper though.

You have several really good rebuilding shops in California. To have them take your starter apart and deal with any wear issues if any. Yours may not even be the original starter.

Two that may still advertise on ebay have good reputations. They also do not use junk parts for repairs.