On a Dart with the springs in the stock locations that's already the widest tire you're going to fit in there. And I'm sure you know they're not supposed to be mounted on anything narrower than a 15x7.5", so any of the "stock steel wheels" are too narrow.
With an A-body 8 3/4 with LBP axles, some kind of disk brakes, 15x8's and those tires you're going to need the backspacing to be near 5". But to know for sure you'll have to measure.
