roadworthy requirments

just went and had a look at qld roadworthy laws.
thing i dont get is if roadworthy laws are designed around adr(australian design rules) how can different states have different rules.
eg.vic roads inspector in the other week to check up on my paper work.(all ok)
i asked him to define the section on lifting and lowering.how high can i lift my gq legally.
in the case of coils/shocks.as high as i like with out having to modify anything(brake lines dont count)so im guessing 3"
and as for body lift as high as i like with out modifying anything(brake lines dont count)so again im guessing 2".
so if thats the case i can legally in victoria lift my gq 5" and still be roadworthy.
well insurance companys will allow only legal lifts ect so there shouldnt be a problem with a 5" lift.
i spoke to our insurance company(direct dial)the lady didnt know how high i could go so i explained to her if i went 5" it would still be roadworthy and was told so long as its roadworthy its insured.
i havnt lifted it and would still get it in writing if i did go ahead.
so the question is how high can i lift a gq with out modifications.coils and body lift.
thank youlooking foward to september(landcruiser park/fraser island)