need ideas for this problem.

First off, make sure your axle didn't shift because 1/2" should have been enough. Of course I don't know where the center of the widest part of your tire was located (front to back). If the biggest diameter of the tire was below the front quarter opening then it might hit when you hit a big bump (when the tire and rim go up into the well). I put 1/4" shims in front of my spring hangers (69 Barracuda). I measured from the front spring mount bracket to the axle on both sides to get the axle square with the body. The only issue you'll have is a slight misalignment of the shock mount studs besides losing a little on the trans yoke. Also, I don't know how much room you have on the rear opening of the 1/4 panel.

treblig