1969 dart wheel and tire size?

Looking to replace the wheels and tires on my dart. I don't have any spring offsets, what size of tire can I fit in the rear without mods? What would the wheel size and offset need to be? I have looked through other threads and cannot find what I'm looking for.

I would like the widest tire in the rear as possible and going to put a narrower tire in the front.


Thanks in advance!