I'd be very surprised if Toyota Australia bring in the Tundra in petrol V8 form. Aussies are very much pro-diesel for large vehicles due to the cost of unleaded here. Diesel is the fuel of choice for heavy vehicles, due to relatively better economy and torque delivery characteristics.
We do have some private companies bringing in left hand drive vehicles from USA and then going to a lot of trouble to convert the steering wheel and pedals and dash to right hand drive for use in Australia.
The conversion costs are horrific, so whilst we can buy a right hand drive Chevy Silverado or Ford F truck through these import/conversion companies, the cost is just OTT, in my opinion.
Let's put it into perspective. $1 AUD = $0.91 USD, roughly.
Do a search on
www.carsales.com.au and you will see that, as an example, a 2008 Silverado 2500HD is asking for AUD$140,000.
To me, that's crazy money considering what they cost in the USA, but the cost of certifying and converting these vehicles is the main culprit. Also, it would be very hard to get parts and servicing expertise for these machines because they are not a dime a dozen like they are in the USA.
Ford Super Duty trucks are also available through these niche importers, and they cost a mint as well.