No one's responded to your info request so I will give you my opinion. I certainly can't comment on whether or not the block can be repaired or comment on what other possible damage has occured due to overheating. I would say that if you can get a good used motor for $2500 I would seriously look at that option. Get an independent to quote on examining your motor and make a decision from there. You can certainly keep your existing motor for parts if things like the timing chain etc are worth keeping. Good luck with what you decide to do.