I don't know how much it cost to produce.That is the issue....they were testing an AWD SRT Dart. What was under the hood was unknown. If it was a new powertrain, they wasted a lot of money for all that to be thrown away.
I suggested the 2.4 Turbo from the Caliber only because they had all the tooling in hand and it would have cost the least. Your 1.75 from the 4C is a good idea, but would they have allowed an Alfa powertrain in a lowly Dodge? What did that engine cost to produce?
I do know, however, that if it can be found in a cheap Alfa hatchback, I bet it could be put into the Dart too haha