Unfortunately, VINs were only made mandatory from 1989 onwards, so you won't be able to rely on a ppsr check with a Torana VIN. You can try using the VIN on pre-1989 cars, sometimes they work, sometimes they don't. The bad news is, you will get charged regardless of whether the records exist or not - even on the govt. website. On the ppsr govt. website, you can try searching with the chassis number for pre-1989 cars, but this could be a bit hit & miss also.
I created a website called www.getppsr.com.au, which charges a premium for a quicker & easier way to get a ppsr check, so I know a fair bit about this stuff. Unfortunately, this site doesn't have the ability to search for pre-1989 cars, as I found it too un-reliable, and didn't want people to waste their money. Depending on the info you're after, you might be happy with the free searches provided by the state & territory govt. If you go to this link on my site www.getppsr.com.au/faq.html you will see a map of oz. Click on the place where the car is registered, and you will be directed to the free search provided by that state or territory govt. Some states provide a lot of information for free. eg. Tasmania provide the engine no., make/model, colour, build year, rego expiry, stolen status & write-off status all from the rego number! This might be because you can't get stolen status records on the ppsr for Tasmanian vehicles yet.
Hope this helps.
Cheers.