From small block to big block

A friend said that he might be able to just sell me a 383 of his that I've had my eye on for many years. Since buying my Dart though I've really no need for it. But that being said, what would I need to do if for some stupid reason I wanted to pull my 318 out of my '67 Dart and instead put in the 383? Current setup is a 318 with a 904.

What will I need to change?