largest rear tire on stock wheelwell 69 dart

I have 255/40/18 tires all the way around. My rear end favors the right side 1/4-1/2". I had to do months of measuring and searching to find an 18 x 9" wheel to fit as perfect as possible in the wheel well without major surgery. Even with all of that, the fenders will be rolled and trimmed.

I have a set of MP offset shackles (0.75") I plan on using in the future so I can attempt to fit a 275/35/18 on all 4 corners.

20150409_090313.jpg