A complicated answer, but here goes...
Offy and Clifford make the conversion for the American C9 DE 6049 flat-top log, and the earlier small log head.
Offy three-carb conversion adapter for '61-'69 small sixes.
Offy three-carb conversion adapter for '70 and later small sixes.
From
http://xpfalcon.kicks-ass.net/Engines/Original Six.htm
The Aussie Flat-top log, 72DA 6049 AC is very similar, and can take the American adaptor for the C9 DE. There are differences between our Stromberg-Bendix carbs, and the US Autolites. The Aussie stoff has a parallel linkage, the US linkage is out to the side.
The US stuff is designed around three options.
3 x three Autolite 1100/1101 or
3 x Holley 1-bbl carbs,
or 3 x Weber ICT (VW Superbug) carbs.
The linkage is simple and works on the US carbs. It is
progressive, and provides good economy with a very heavy opening of the outer carbs. Cobra Six complained that this could make day to day driving a little tiresome if you wanted to 'plant boot' (my words intimating his comments).
Using Aussie carbs, your on your own with Aussie Stromberg jetting and linkage. The system could be to use smaller 66 Falcon XR 200 Strombergs, and use the Redline or Lynx linkage kits used for Weber carbs.
Look at the Ford Falcon Performance site, and Cobra Sixes sites. My suggesting is swap a 2V head for an Offy set-up form one of the six other US guys on site using the Triple Offy adaptor on there small Log (pre 1966) heads. This is similar to the 144 to 200 heads in used up to 1969.
