Magnum engine in an A-body?

I know, I know - it has probably been covered a million times. I searched a bit and didn't find what I was looking for.
Basically, I'm 26 and have grown up with fuel injection. I like it, I get it, I want to keep it. On the other hand, my old man always had muscle cars and I want one of those, too.
I understand the wiring issues involved.
What else would need to be done to fit a Magnum series 5.2 or 5.9 into a 72 Dart? Engine mounts? Bellhousing patterns? Anything else?

And what kind of performance can you get while keeping the EFI, anyone know where to go for that kind of tech?
Thanks for any help guys.