slant 6 / 318 swap

I`m not sure about 63 or 64 but I have used two dusters to up grade a 65 Dart and a 65 Barracuda. The rear ends fit so I had larger rear drum brakes and was able to add a leaf to the rear springs as well. Proportioning valve worked master cylinder worked I didn`t have to buy anything besides replacing control arm bushings. Gives you the larger bolt pattern so you can put just about any style wheel you want which is a big plus since you can`t get many custom wheels in the small pattern