Noone ever realizes my hemi is all aluminum w/ a KB block until I tell them. Never liked the all aluminum look myself...prefer some orange under the hood.
I even had people at the track think my Indy headed 440 was a small block. It was actually smaller at 446" than some of the small blocks I've raced, lol.

Like everyone else said, if you paint the heads, I doubt anyone will even notice they aren't factory. Unless you go to the Mopar Nats or Carlisle, but then you'll get ripped apart for the plug wires not being date coded.