Philia_Bear;c-150692 wrote7/9 brakes don't fit and are not easily adapted
P2 brakes fit using an adapter
The Americans make it out of aluminum
Options of up to 336mm+ are easily bolt on using said adapter
Which would require pretty much every brake test on the list to get engineered. If one person does it though, documentation could be used to make it easier/cheaper for someone else doing the exact same setup.
Other alternative is adapting an entire system from another car. May be more viable if for example your already doing an axle swap. If it's a complete system swapped over you don't have to do all of the brake tests.
I'm nsw anyways, not sure about other states.
All that said, most builds I have heard getting engineered haven't required brake upgrades noting it's already a 4 wheel disc car and hence ahead of a lot of cars of the era.