Ive just put 18" 8.75 et20 fronts running 205/40/18 tyres and dont scrub the arch with around a 50mm drop and 18" 9.75 et20 with 225/40/18 on the rears same drop and had to roll and flair the arches a little bit of cutting and 3.25 degrees negative camber ( maxed standard adjustments) so they dont rub, dont know if this helps any1 thats wondering how wide they can go.
Cheers
Dom