All Americans are crazy, but we love you guys anyway!
First up, the wisdom of the OZ 2V /US 200/ Modern T5 or C5 swap is made known by the wide smiles from people such as Mustangaroo, his son Jason, Ricksmol, OffenokeeComet, Mraley, Kastang, Slade, AzCoupe. There are many others walking in there foot steps doing ArgieSP or ME or Aussie 2V head swaps onto US blocks and counting the costs. You should wait until they talk.
A few points to note
1. The Aussie 250 block is a liability unless it come with a Top loader or factory C4 in good shape. Any head separted from the block will need reconditioning and components to link to the US 200 or 250.
2. If you have to rebuild the block and transmission, the Aussie 250 2V with a C4 starts to look good.
3. Then it looks bad again becasue it won't fit under the hood of a Mustang without some work on a remote mount air cleaner
4. All people here who have done the 200 2V have eventually appreciated that there is a big cost involved in doing it yourself.
5. Out of the 23 or so 2V heads listed in a post by Mustagaroo back in 2002, about 35% of the buyers (about 6 people) ended up putting the heads on there car in two years. Of those, 4 or 5 are really happy. A few have opted out due to the cost. Now, there would be more than a dozen 2V 200's around.
6. The value of the complete and reliable 2V 250 package landed in America, could be a minimum of US$2500. The cost of doing a 2V head and American 200 or 250 block to suit is probably more than that.
7. Those who pay up front for the complete Head/Block/Bellhousing/Gearbox package would have a long term saving, but most Americans want a 200/T5 combination, and that is a lovely package.
8. Check out the Crossflow Chronicals by Jack Collins. He used good contacts in Australia to get his X-flow, and picked up the whole Head/Block/Bellhousing/Gearbox package and then rebuilt it himself, and added a great EFI package.
Enjoy the 2V ride, your gonna love it!