Am..........no
Just like any state, you make a modification/s that is untested, then yes they are illegal. You get an emissions test and prove that the car still complies to the emissions, for that year (ie: 1995), then they will pass. Unfortunately each test, in VIC, costs $1500, so if you fail the first time, that's another $1500 to test again.
Just ask Mav. He had lengthy discussions with the EPA officer, who commented that cars with bigger turbos, inj, power, etc, than his car (280rwkw), passed running ecu's like Pfc, Wolf, Motec, etc... EPA even passed Mav's car with the Greddy plenum and fmic, without any testing required.
EPA is not the pack of a'holes everyone makes them out to be.
PS: Congrates Guilt-Toy!! That's an awesome effort