NEW 4.6 Intake Manifold! Purplemustang!

Hopefully that thing will perform.........because it sure as hell doesn't have looks going for it. :D

And with the basic cube shape, I would really be worried about fuel puddling for nitrous users.
 
I'm curious about this as well. On a n/a vehicle, I don't see much gains. Seriously, even if you manage to port and polish the inside to smooth out flow, still, since it's made of metal, its going to heat up which goes back to the whole issue of "hot air vs. cooler air" and "metal intake material vs. plastic". However, I'm not going to knock the guys work. I say give it time and lets see what results it gets. Forced induction vehicles, however, might be a different story.