Overclock M3N78-VM GPU

I have a simple build setup. I'm simply looking to get the most out of the GPU for the ASUS M3N78-VM. The CPU overclocked very easily thanks to AMD's black edition X2. I only had to up the multiplier. I'm now looking to give the GPU a boost. here is my setup per CPU-Z





What is the best GPU frequency to Shader frequency ratio? The bios default is 500/1200. This board lets you change them independantly however with no fan on the GPU chip there is a danger of overheating the chip. I monitor board and cpu temps and have alrams set so I have some safetys set but I dont want to accidently bake it, well not for too long anyhow. Any suggestions?

I'm also using 4GB of Corsair 1066 memory CM2X2048-8500C5. I'm not looking for extreme measures here. Just a solid overclock if anyone has had success at doing so. I know many use PCI-E cards, this isn't an option. I had to sell my 9600 GT to pay an overdue bill. I need results for a poor man trying to make the best of what he has left.