My dream dart in Massachusetts

For cruising around in a slant six car, properly working drum brakes should be more than adequate. Finding 72 & back disc brake setup will be difficult and expensive. Later 73 & up front disc brakes will mean switching to large bolt pattern on the front and will noticably widen the front track significantly wider than the rear. The front wheels will be pushed out to the edge of the sheet metal. I believe the majority of aftermarket disc brake conversions require larger wheel sizes so you wouldn't be able to run stock 13" or even stock 14" rims and wheel covers on your Dart. Thats a beautiful car and that yellow works so well on Dart convertibles. I really hope you are able to keep the stock wheels on it.