You will nee the correct 'T' case, AWD front diff and the SmartTrak computer and wiring harness. I don't know if it interfaces with the BCM but it may. The system uses vehicle speed and output shaft speeds to direct the torque.
Bravadas have 3.73 ratio gears, hopefully your CC has that ratio in the rear.
Best Regards, Jim
2004 Tahoe, Summit white, loaded up. 06 front air dam, wood interior trim, Shaved Roof Rack, Escalade rear vents, LED Tails, SLP dual cat back exhaust w/ Flowmaster 70 muffler, 20 inch 07 Sierra wheels.