I upgraded from the standard 10.5" Diameter to the 11" Diameter rotors. I would think you might need to switch to a radial mount caliper to go to a larger diameter yet. A radial mount caliper would not have required modification as the Wilwoods I had required modification to prevent hitting the upper control arm.
Club Cobra - mvanhorn8893's Album: Front Brake Rotor Upgrade
I'd also like to learn if anyone has went to a larger rotor and how they accomplished it.
Mike