Bore limit on a 68- 383 ?

I have a 68- 383 that came with my barracuda.
Was locked up, was told was a new rebuild that went bad on the start up.
Then left to sit for a few years and some how got water in a cylinder. After breaking down the engine. Seems story is true. Still had break-in grease on parts.
It was bored 40 over.
I'm wondering if I rebuild this block... How far can I go on a bore if it needs it?
60 over+?
I've heard you can go pretty far safely. Any truth to that?