OZ UTE Question

They had 273s available from the factory, depending on year; so if you're converting from a slant it can be done with factory (Australian) parts.
Depending on the series, AP6 Wayfarer (equates to the US early A), the VE-VG (similar to US '67 and up As), ending with the CL (no relatives in the US).
If you're keeping it RHD, exhaust is Aus. only- manifolds or headers (extractors) like those made by Pacemaker are needed. Remember, the Aus. As still maintained the right side engine offset, so with the steering box and column on that side too, things get REALLY tight. And you thought US A bodies had tight engine compartments...
If you're converting to LHD, you should be able to use US/NA parts, along with a firewall/dashboard swap.
I'm sure when Cal or Bewy show up (it's the middle of the night there) they'll correct any misconceptions I may have stated. My knowledge is limited to what I picked up from people on a visit 40 some odd years ago...