275/60 with stock wheel wells?

I've got 275/60/15s on my 68 Dart with nothing more than a simple 1/2" spring offset. How much smaller are the Valiant wheel wells?


Now that is what i want to hear! haha. Rear wheel well should be about the same on dart and Valiant. Im pretty sure front fender opening is lower on a valiant though. (but that doesn't matter for my question).

Do you know what the backspace is on those wheels??