Put a set of autolift1000 air bags in the rear, the spacer that protects the bag from lower coil over mount alone will add about 3/8" height to the rear then you also have bags for susp. improvement, you can always add a few lbs of air to bring it up a bit if needed.
I had to do this when I had the stock 7.5 rear set up and running a 15x11.5 Et Streets, or it would hit the outer wheelwell lip and the frame where you are talking about, this fix my problem! But it did raise the rear of the car a little more.