If you are planning to use this on road, I would check with the state authority - I think you are in Qld, and there was someone thre having a great deal of difficulty with a Landrover Game - which actually came form the factory with wider tyres, although not as wide as you are suggesting. There is now a legal limit on increase in tyre size in Qld and probably most other states. (even with an engineer's certificate).
John
