A boy and his Station Wagon..
This is one cool build. I love the small wagons, unfortunately I couldn't find a Dart or Valiant when I was looking so I ended up with a Ford. I can't wait to see your Dart when it's all done (maybe with some ralley rims...)
On a side note, my Swinger has an almost identical power train as your wagon and it runs on 87 all day. It's kind of nice considering the 87 octane costs about $4.60 a gallon where I am, and 91 octane is about $5.15 a gallon.