I would agree with coolfalcon regarding polishing the exhaust ports. I'd also recommend unshrouding the chambers and polishing them. It'll help reduce the likelihood of forming hotspots in the chambers and causing detonation. What intake are you going to run with your heads? The reason I ask is the Weiand X-celerator intake is basically preported, so using something like that with unported Aussie heads will result in a mismatch at the port opening. If you're not using the Weiand intake forget I mentioned this last part...
You know, I was planning on using a weiand x-cellerator intake manifold. It looks like it would work pretty well, but its a little detering that it is already ported and I didn't want to port the heads. I hope I can find another manifold that will work well. Out of curiousity, how big is the port on the weiand? Is it a 2V gasket matched port or just a little bit bigger?... because a small port wouldn't hurt, it still wouldn't be anywhere near the 4V monsters.
Speaking of 2V Aussies, has anyone ran across any flow figures on ported heads with the small valves? I have seen Powerheads numbers. Those heads must be Aussie 4V closed chamber heads (62 cc chamber and 2.19, 1.71 valves). I have seen the stock Aussie 2V numbers as well, and they apparently flow less than an open-chamber US 2V head.