Im running 31x10.5 16 Silverstone Xtremes and what i had to do so the wouldnt rub inside the front guards was remove the inner plastic guard and flatten the panel lit a bit.
There is nothing you can really do about them rubbiung on the chasis as the GV's dont have steering stops.
Really close. Actually rubs when turning in reverse.
Marked where it needs more clearance.
Lots of mud behind plastic panel
Fold flap straight then hammer flat.
All flattened and sprayed black
Heaps more space.
Gained about 10-15mm and took about 1/2 hour to do.