Should I go Big block or Small block?

Have had he same dilemma. I have a fresh 440 in the garage but am going small block. I'd rather have power disc brakes and be able to put power steering on the car if I want. I have a buddy with a 600+ HP stroked big block in a 68 Dart and said he wouldn't do it again based on the tight fit, extra money to do it, and the fact that his car isn't tubbed to handle it!