IIRC (and there's no guarantee that I do), the 575 and CC pinouts are identical; the case surgery involved is to move the cable harness edge connector further towards the case front to account for the length of the 575 logic. If you can live with the logicboard sticking out an inch or so from the back, or make up a box to surround the excess, you can do the 575 conversion without internal surgery.

*BUT*

I recommend checking my recollections against the Power Color Classic pages over at Applefritter.