Paging Jim Rhinehart (Rhinodart)

Heres a link from Hemmings with some background. It gets confusing...GSS, GTS, Mcode...lol. Your reasoning makes sense Darwin as you could factory order the 383 on the 67 S cuda. Why would they need Norm to do the exact same thing to a Dart?
Hemmings link has no mention of the 383 Barracudas.
https://www.hemmings.com/stories/2013/07/01/mr-norms-marks-50-years-of-making-mopars-faster
That story is a fairy tale. Plymouth was already putting 383's in Barracuda's from the start of the '67 model year. All Dodge had to do was use the same DS manifold as Plymouth to put a 383 in a Dart (same engine bay). I'm sure the Chrysler engineers could have figured that out. They didn't need Norm for that.