Knobby,
You could be in trouble here fella. THe law states that the tread of the tyre must be covered when looked down on from the top. If this is not the case then it won't pass an MOT and will more than likely get you tugged by the Boys in Blue. Looking at the pics it looks like the G60 arches should cover the tread and make you legal. But I think to get those wheels to clear inside the arches to lower it is going to be really hard work as they stick out MILES!
Good luck,
Nick