If you've still got the stock stump-puller rear-end, I suggest keeping the 250...
I have one in my '72 C-10, and it is a fine engine...
These are all (230/250/292) seven-main bearing engines, and the bottom-ends are nearly bullet-proof.
However, the 292 is a LONG-stroker, and if your truck is spending a lot of time on the highway with that 4.11 rear, the 292 won't like that too much...(neither will your wallet at the gas pump).
I 'd vote for the thread repair if the rest of your engine is in decent shape...
If the 230 is in good condition, it might be a good runner, but it'd be worth tearing down for inspection before dropping it in...
So now I'll ask the question: what's involved in putting a 230/250 into an AD chassis (let's say '54 - '55 first) ?