5.2 Magnum Build

I have a Dart Sport with a 6 and want to swap in a small block. I have a 2001 Ram van with a 5.2 "Magnum" in it that still runs pretty strong with 195 k on it. The rest of the van is nickel and diming me to death though. I read an article about a motor like this making 400 hp on a "budget"...any thoughts? Thanks