1968 Barracuda back space question

This is what it looks like. 255 tire

View attachment 1715098081

Exactly. The outer edge of the sidewalls on those tires are already sticking out past the outer edge of the quarter panel. I'm sure they don't rub with the car that high up in the air, but if you lowered that car down to anywhere near stock ride height those tires would never work. On the bright side, you can run any width tire you want on that car, they'll never rub. You could run 335's, just hang them out further. You might have to run mud-flaps at some point I suppose. What actually fits inside the wheel well is a non-issue at that ride height, there has to be a good 3" or more between the top of the tire and the wheel opening. That covers all the suspension travel on compression.