first was the HB Torana which was based on the Vauxhall Viva, then the LC which shared the same floorpan as the HB/Viva, but stretched a bit I think. the LC had all Australian styling and uprated suspension and stretched engine bay to fir in the Holden inline 6's. After the LC was the LJ which was more or less very similar to the LC. Then the TA Torana which was something that nearly no-one remembers, then the LH which was a sedan and scaled up in every dimension and introduced V8's to the Torana line. After this was LX which was styled very similar to the LH and introduced the hatchback variant to go along with the sedan. LX brought more than a new body style though as it went through massive suspension and engine upgrades, but from memory the upgrades were introduced later in the LX's life cycle. after that was the UC Torana, and the UC Sunbird that was based on the Torana (sunbird name was also around during LX I think, but that was the Holden Torana Sunbird, as opposed to the Holden Sunbird). The UC brought a much 'newer' appearance to the front nose of the Torana and the tail lights, and an updated interior as well. V8 option was killed in this model. UC is typically the least-liked of the models as it's kinda on the ugly side. People typically like the older 70's muscle look, rather than the UC's late 70's disco-image. the Torana ended after this, replaced by the Commodore - itself a fairly heavily modifed Opel from Germany (can't remember what it was called in Germany though). The Aus Commodore and the German Opel model look pretty much the same, but the Aus models body has significant strengthening. The Opel model was imported for testing and apparently shook itself to death on our shitty Australian roads
The Kadett was originally an Isuzu IIRC. in Australia we got it as the Holden Gemini.
The LX and UC hatch's look similar to the Opel Manta, and the Chev Monza, but aren't actually related
I'm pretty confident what I've said above is right - I'm a Torana nerd but it's also been a long long time, so my memory might be faulty on a few points
