The biggest tire I can fit into my lowered 1200 without flares or other mods in the front has been a 195/45-15. Even if you flare the car, with a 15" wheel/tire you're still going to have a challenge keeping it off of the innards of the fender at that rear part that's rubbing because of the larger diameter of the wheels. My best advice is to have a front end alignment done. Tightening up your tension rods may help a little bit, and/or replacing the control arm bushings.