Overclocking my 6950/6970

Hey community,

So I just realized something about my computer. I've had my reference 6950 flashed to a 6970 for quite some time now, and never really realized that I did not overclock it correctly. On certain games it would crash, and it would be a display driver crash. I would think nothing of it, because I've had a display driver problem before, and thought it was more because I was playing alot of games. It would only crash in the most demanding games but only after a few hours.

Now, would anyone be able to guide me in the right direction on what I need to do to the card? I'm using MSI Kombuster to run the stress test, because that seems to work well, and its kinda dual purpose in that I'm trying to check the overclock on my 2500K as well.

My clocks on the card are as follows. I think I need to clock up the core voltage, but you guys are better at overclocking than me.

Core Voltage:1150 (stock)
Power Limit: 0% (have no clue what this does)
Core Clock: 920MHz (880 stock 6970, 800 stock 6950)
Memory Clock: 1400MHz (forgot the stock speed)

My fan profile is set well; the card doesnt usually exceed 75C or so under a stress test.

I want to get the most of the card possible. 950 is the max core clock and 1450 is the max mem clock. I would prefer to get close to that.