How many cubic inches is a 383 bored out 60 over?

A 383 Chevy is a 350 block with a 400 crank bored .030 over. If it's not bored oversize it's a 377 (Not the only way to make a 377). If it's .060 over, it's a 388.

Most builders agree that you cannot safely bore a 350 block .090 over, but if you did the resulting engine would be about 394.