Too easy! Any log head one will fit, from any side of the Pacific!
Belive it or not, even the late 80's x-flows have their part number stamped 72 DA 8594 AB. That means the X-flow item first got minted in 1972, and was used on log heads before it ever saw duty on an x-flow. It is the same as pre crossflow 2V's and Log heads from 1972 to 1976. I think you'll find a US one will fit fine.
The bolt pattern is the same, but on the log and 2v's, the spout travels up, on the cross flow, it travles out level. The position of the bolts on the head are turned 30 degrees, but the device reamins the same.
There is often the provision for a TVS vacum tree on Aussie heads after 1976, so if you want to use the emission control, then you'll want to use a US Falcon one that has the 1/4" connection. Most of yopu guys won't be doing that, so any US 144/170/200/250 I6 bit will fit!
Deano