Backball it will apply with respect to lift and also increase in tyre diameter where there are maximum allowable limits. I'm not sure if Vic has its own rules/guidelines or if they have adopted the NCOP, but it may be worth reading the wheels/tyres and suspension guidelines from the VicRoads website (I assume) or speaking to their registration engineers. I would be very wary about listening to people on forums re registration rules, based on my knowledge of the rules in NSW and the sheer number of people that state incorrect rules - get the info from the source. I'm sorry that I can not be more specific about what you need to comply with.

