275/60 with stock 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??

I had Wheel Vintiques make custom offset steel wheels for me. I wanna say they were 4.75" BS, but I can double check tonight when I get home. Keep in mind every car is slightly different so what worked for my car may not work on another. There are just way too many variables. You just have to be diligent in your measurements and see what you're actually working with. Don't take what you read on the internet as gospel.