70 Dart Front Wheel Question

Yes, I have a set of brakes from a 73 Duster.

Ok, then with those brakes and a 15x7” you need a 4.25” backspace and you can run 225/60/15’s. If you run less backspace than that, you’ll have to run narrower tires. The issue is that a lot of aftermarket 15x7’s only come with 4” of backspace. With 4” of backspace on a 15x7 a 215 is pretty marginal for clearance, it can be done but it will depend heavily on your ride height and the body tolerances on your car specifically.