Max tire size on a stock rallye wheel / setup ideas

Hello,

Can anybody tell me the max width tire that can be safely used on a stock 14" rallye wheel (5.5" wide if I'm not mistaken)?

This is for my totally stock 1970 Dart. I'm looking at either of these setups:

225-65/14 rear
215-65/14 front

Or

225-70/14 rear
215-70/14 front

Or

215-65/14 all around.

Is there much difference between the 65 and 70 profiles? Some pics and opinions would be very welcome!

Cheers!