Tire sizes for 14 inch wheel drive 1970 Dodge Dart

On my '71 Swinger I have 215-70R14 tires front and back on the stock 5.5" Rallye wheels. They fit with no rubbing.

Yup, those would be fine on 14x5.5’s. They’re also the widest recommended tires you can run on 5.5” wide rims.

Not that people don’t run 225/70/14’s on those rims, I’m sure some people do. But the tires will be squeezed down a bit to do it, which messes with your tread pattern. And some shops just won’t install tires if the rims aren’t within the recommended specs.