Is the 383 a better engine, or does the 440 just have more displacement?

I know a lot about small blocks, but not as much about big blocks. I hear and see all the time about people building 440s for their cars. My honest and serious question is, "Is the 440 a better engine than a 383, or is the only advantage the additional 57 cubic inches?" Also, what is the weight differences. I would think that a mildly modified 383 with good heads, intake, headers, etc. could easily hit 450-475 HP. The blocks have the same dimensions, don't they? I mean that won't a 440 fit in exactly the same space as a 383?