318 to a 390 or 392 stroker?

My grandpa who's an old racer that knows ALOT about mopars told me a while ago that when you bore out an engine, bore only what is needed to make the bores nice, if it only takes 30 over, bore it 30 over.

Good advice. I'm only going to do it .030 over just to be safe after it gets tested anyway.