Trimming inner fenders
I trimmed about a 3" by 11" strip out of my front ones, just on the inside of the lip and parallel to the driveline. The rubbing went away. It got even better when I switched to the B-body spindle and 1LE 12" brakes, because the spindle changes the geometry and wheel spacing a bit.
With that small a trim, water doesn't come into the engine compartment - it only goes into the inside of the fender. Since I live in NorCal, that doesn't matter, but if I lived in a salty state and/or drove a lot in the snow or winter or rain, I might not recommend it because of possible rust issues inside the fender.
BTW, I am running 16X8" wheels, with a 245/45/16 front and a 245/50/16 rear with no more rubbing issues. As soon as my new rears show up, I will be running 245/40/17 front on a 17X8 wheel, and 275/40/17 rear on a 17/9.5" wheel. They measure in correctly, but I am dying to see!
Jim