It's very hard to be done NA. Not impossible but not worth the effort.
Heads arent bolt ons
the C heads seem to perform better in an NA application but all that work for maybe 400 RWHP if you do it right doesn't seem worth it.
I dunno. Even the new 5.0's are mediocre but a big step up over the turd 4.6. But it's a real cobra so I'm not sure how much I want to molest it. Ford gais will still pay money for these things