Needing more

Is there any way to go past the 1000MHz cap on the core of my 6870? MSI Afterburner and CCC all cap out at 1000. I'm rock solid stable right now, and I'm wanting more.

You would have to use MSI afterburner and enable the unofficial overclock option, that should unlock the 1Ghz cap on any card. To enable the unofficial overclocking, it is necessary to edit the MSIAfterburner.cfg file located in the installation directory of AfterBurner (typically Program Files (x86) MSI Afterburner):

You need to alter the following:
Seek UnofficialOverclockingEULA and add following text:
I confirm that I am aware of unofficial overclocking limitations and fully understand that MSI will not provide me any support on it
Set UnofficialOverclockingMode to 1 to keep PowerPlay active (may not work on old ASICs), 2 to traditionally disable PowerPlay or to 0 to temporary disable unofficial overclocking path
I have done this on my XFX HD5770 dual slot card and achieved an overclock of 1003Mhz.

Thanks