Okay - after plenty of reading up have decided I want one shot at this and don't want to end up changing them in 6months time!
Am looking to go as wide as possible without a big step up in diameter(height) so have found some Kumho 834MT 31/11.5s on 15" deep modulars which look pretty sweet! Fitting extended arches, trimming and swapping bump stops will not be an issue. Would I have to go for a lift aswell? Website states it may not be required depending on whether the springs have sagged. If I do - would 1" lift be enough?
According to a few tables on tinterweb swapping from 235/70/16 to 31/11.5/15 would result in a diameter and width increase both of 2" (smaller diameter than previously recommended 265 75 16).. Help muchos appreciated