Brad, some people say that raising PCIe clock can help with higher clocks, I set my PCIe clock to 102MHz, I have managed to get my chip to 4.6GHz with 220Bclk, haven't tried for anything higher, but these boards tend to have a Bclk wall of 222MHz unless you hardmod them..

If you are handy with a soldering iron, you could PM hicookie and ask him for the hardmod instructions.