Hey Chardon!
I recall running my E8400 @ 3.750 Ghz with my P5N-T and a BFG 9800 GTX OC+.
The BFG 9800 GTX OC+ has a core clock speed of 760 which is also overclockable safely to 820 Mhz in my books. Yes it is done higher but that is the speed I like. The memory is a bit more limited though.
Anyhow when I OC'd my 8400 @ 3.750 Ghz I recieved a 3dmark of 16,500 marks.
The main problem is your 8800 your using now. But i'm sure you understand that it is the older chipset and holding you back.
The newer cards require us to O.C our processors to reap the benifits due to the new generation of our cards. The CPU is the bottleneck now.
So yes you should hit a similar score if you go with the 9800 GTX OC +
A question I will forward to you is: What is the brand and the full model of the card?
PS: If you wish to reach me and throw some questions feel free my MSN is
Topsecret66server@live.com