What back space for 15 x 10 cragar S/S wheels on 67 dart

You can probably fit darn near anything you can find up to about 28" tall and with a section width up to about 13.5".

On my '71 GT there's about 14.5" from the stock quarter lip to the frame rail. 72BBswinger is running 335's on his mini-tubbed and spring relocated '72 Dart.

There's a few examples in this thread, just ignore the Duster as that's a different ball game.
Widest rim and tire for full mini tub to frame