What size tires will fit on stock dart 15" wheels?

I need to know for my build (1970 dart) what size tires will fit without rubbing on the front and back (I know the back may be wider, but I need to know the widest for both). The rear springs/rear mounts have been moved in a little to add a little room in the back by the previous owner...
Also, I am probably gonna use Wheel Vintiques Rallyes 15x8 smallbolt that have a backspace of 4.625 offset +3mm in the back and the same wheels up front but 15x7 Rallyes with 4.25 backspace offset +6mm...
Will those fit (even the wheels)? What about tire size on those wheels?
Please help!:banghead: