Ok , need to step back

if it ain't broke....... that Dart sounds like a badass car and there's a cool factor with that bored and stroked 400... you know what to do, cut your losses and put the Duster up for sale with the 340, chalk it up to an experiment you shouldn't have attempted.. recoup some bucks and move on. ...or you can spend another year working on it. :BangHead: JMHO.
Thats my thoughts