You'll probably need an engineer's certificate - since there's going to be a fair bit more power, the chassis may need to be braced to limit flex, and the engine mounts will probably need to be custom made. You'll probably need bigger front brakes as well. A friend of mine did this once with a Datsun 120Y - he shoved a worked 1800 under the bonnet - and he needed the certificate (admittedly, this was in NSW, but it's probably the same in Vic.) It was real fast, but it wasn't an easy job.
Good luck, mate.