The 383 is every bit as easy to install in an A body, so what's not to love? Plus, it has the distributor staring you in the face when you open the hood, instead of having to reach for it.
I love them both... equally... and some say "you can't" ... LOL
They both have "plus sides" to them. But my choice IF we are talking A-body and in the 300-400 HP range (where I mostly play), I would personally take the 360 mated to a 904. As I stated earlier, for header options, and the 904.