You didn´t noticed that one ?.... 8800GTS 320MB, one of the cheapest Direct X 10 capable cards around, fresh from oven. You want more overclocking headroom? A bit more voltage may help would you think? Ok then let's go.
First right at the back of the Graphics Card, you can measure the voltage of the GPU core and the voltage of the GDDR3 Memory. Use your multimeter to measure at the points marked below..... VR-Zone