Who's idea for the 68' Hemi Dart

From what i understand in all of the previous articles that i have read, these cars were all just quickly slapped together cars at Hurst.
They were simply the ''bones'' that a racer needed to build a competitive race car.
It was expected of them to take the car home, take it apart, paint in your color scheme of choice, and blueprint all of the mechanicals before actually running the car at the track.
The engines and the wheel alignments were only intended to drive the car onto a trailer and into a shop before they were fully prepped.
Not to mention the wheels and tires, lol.
As delivered, i can believe the 500 h.p. rating to be accurate.
After all, they were just hastily slapped together!