I'm getting a 408 storker built by IMM Engines. Brian said he is going to break it in on the dyno. I don't know his exact procedure but I'm inclined to think he is going to "let it rip" after everything checks out.
I've been wondering same question myself.
I've seen numerous vids including the one IMM Engines has in which they build the engine, put it on a dyno, and run the snot out of it. So I guess the correct answer would be ... run it hard.