I'm assuming you are talking swap into a Dart you already have.
If so, I doubt I would bother with a swap to a 383, ESPECIALLY if it already has a small block. 440 or stroker 400 would be my minimum, to put up with the tight fit.
If it has a slant, either is possible. If it has a 273/318, a 340 or 360 is a no-braner, imo.
Bottom line for me? It comes down to what you have. I have all big block stuff, so a 440 would be my go-to.