67 Notchback disc brake/suspension questions

First, tighten up every bolt and nut to spec. Second, get a good alignment from someone good that knows Mopar cars. The alignment shop should also find any problems. As said before, these cars can handle very well. Next add a front sway bar. I'd try some good brake shoes before you go through the trouble of swapping to disc brakes, if your drums are good. Assuming you have 10 inch brakes.

Firmfeel Mopar Suspension and Steering