65 Valiant

Great buy! The only way I know of that would get a resonator would be the 273 4v aka. Commando V-8. I'm also not aware of any package on the 65 Valiant or Dart that would include the Commando. It would need to be ordered a'la carte from the list of available options. Conversely, the Commando would probably require 904 or 833 transmissions as well as HD cooling. The VIN isn't going to tell you which engine was in it because Mopar did not distinguish between the 2v and 4v versions until 1967. If the car is essentially a Formula S Valiant, it should have 14 x 5½ wheels on it.

The notch in the valence looked a little large. I went through some old photos and found that the size and location seem to be correct. The entire system is available in repro $$$. It makes good music for a single. IIRC the 65 used a muffler that was like a Dynomax Ultraflow. It was basically a louvered pipe with an S-bend in it installed in a casing to look like a muffler. They must have heard the complaints in Detroit because the 66 models had a reverse flow muffler.