It's awesome seeing a car like that kept by the same person nearly it's entire life. And it looks like you've taken really good care of it. Makes my first car look like poo!
They only made 457 1967 GTS 383 Dodge Darts and 229 4 speeds which is what I have. Also Mr. Norm is the why a 383 got into a 67 Dart. Dodge told him the engineers said it wouldn't fit and he had a mechanic put on in a 67 Dart, told Dodge and they wanted to see it so he drove it there to show them.