Maximum bore on 383

I'm tearing down a 383 with hopes of rebuilding it. First problem is someone has had it apart in the past. It's a stock 4.25 bore but someone used a ridge reamer, well tried to use one anyway. Lots of material removed, so my question is what is the largest over bore that a 383 can go? I will have it sonic checked but would like to know what the possibilities are.