By "they", I meant, your steering knuckle and an SVT's steering knuckle are different I believe.
The larger rotor would 'usually' dictate a larger mounting bracket, different caliper, etc., which, would 'usually' mean you would need the whole assembly.
We'll have to wait to hear from someone else on who knows for sure.
One good way would be to shop for the knuckles for the 2 different cars and observe that they are different part numbers from every manufacturer who makes them.
That would pretty much mean that you need the SVT's knuckle.
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