What I have learned so far.... (And please correct me if any of this is wrong)
28 spline axles were the only axles across all AU models.
The spread of ratios are 3.08, 3.23, 3.45, 3.73, 3.89 and 4.11.
I haven’t been able to determine exactly which ratios came out in which AU’s, with ute, wagon, sedan, XR’s all being different. Similarly I haven’t been able to determine which specific models LSD’s came in, and which are interchangeable.
Some vehicles being leaf sprung, some live axle coil, and some
IRS means that complete diff swaps between models are not always possible.
Some AU live axle sedans have smaller diff housings/3rds that will only take 3.08 Ford gears. VL Commodore 6cyl R & P’s have a 3.45 ratio that will fit this AU diff.
Slotting in a 3.45 LSD diff housing from and EL into an AU won’t work easily as the EL diff is 70mm shorter disc to disc than the AU.
That’s about where I’m at at this point in time. If you have info you know is correct and has worked please post it up.