Thanks to Don Griffith:

My son was looking on the internet and came across some pictures that looked like our car. After some investigating it appears we own a 1966 D/Dart.

The vin number begins LO23 and all other features are the same as indicated in the website. It still has the rubber plugs in the rear seat belt delete. I have owned this car since 1974. I have done a title search on it and have traced it back to where it was purchased in Kansas City in August of 1967. I have talked personally with several of the owners. The original owner has passed away, but I did speak with his daughter in law.

She remembers him tinkering with a jet booster (Turbonique drag axle). He installed it under the car at the rear axle. Have since found an article about this drag axle in an August 1966 Popular Hot Rodding magazine. It was not on the car when he sold it. Other owners remember it having a very steep rear axle gear. The car has had a very rough life the last few years before I bought it. I am hoping to talk to some more of the owners to find out why the car was in the shape it was in when I purchased it. My son and I are hoping to start restoring it soon. I don't know if the engine is original it has no stamped numbers on it. I would like to find out how to document it further.