arch extentions

[cuz 62]

just bought these off ebay i want to fit 31x10.50x15 tyres on them i have a narrow bodied 1992 2.4 surf does anyone know if i have to fit arch extentions and where i can get any i have looked at the ones on 4x4assessoriesandtyres site but they dont really show what they look like any ideas anyone please
ps the wheels are 15inx8in

[Gamedawn]

That really is a piece of string question. It depends on a lot of things, amongst which is the offset of the wheels. This will determine whether the front wheels foul on lock - if they do you might have to fit spacers to solve that problem but this will almost certainly mean you need flares. I think the only real answer is to try it and see.