IIRC the 04 and 05 have a 65/35 R/F torque ratio, and the 06 and 07 have 59/41.

Yeah, the DCCD (Driver Controlled Center Differential) is a pretty complex system... It actually doesn't control the amount of torque, but basically allows the front and rear diffs to spin at different speeds. For instance when we have our DCCD at full open (full rear) our front and rear wheels can spin at any speed they want, making it super easy for donuts. But when you put it in full lock and take a tight turn the wheels will try to skip because the diffs want the front and rears to spin at the same speed and when your turning tightly they won't.

That's the best I can explain the system, and I've read over it a few times. I can't seem to find it now (2 links are down), but there was actually a 17 page paper written on it.

And I'm not sure if Ken Block uses the DCCD system in his STi. If he does, I'd assume he's using at least one of the lowest 3 and not Auto (auto will try to adjust to make you not slid).