'64 Dart Cragar S/S Size & Back-spacing

I've got a set of old 14 x 6 Cragar S/S all the way around on one of my cars. Use a 205-70R14 on the front and 245-60R14 on the back. I've got a later production set of Cragar S/S on another car with 14 x 6 on the front and 14x7 on the back. Seems like the backspace is listed at 3-3/8 for the front and 3-5/8 for the back. Using the same tires on this car and the rears look a little wider due to the rim width. Upper outer edge of rear tires runs close to the inner wheelhouse but have never rubbed. They didn't make the SBP S/S in a load of backspace options though......