it depends on the mobo you get,how you overclock it,its best to do it inside the bios though, lotsa post in the forum for first time overclockers.
Anandtech,toms,dailytech,vrzone, have all shown that the 8 series cards are bottlenecked by slower cpus. Its not an opinion, its a proven fact that the 8 series performs almost 30% better on a c2d over a pd. If thats not a bottleneck, what is it?
You obviously have no idea how a bottleneck occurs in games. You believe everything you read? A cpu performs many functions during a game. Physics, A.I., sound(unless you have a creative card), gfx driver, networking, etc. The gfx driver takes up roughly 20% cpu cycles on avg., less if you have a fast c2d. Heres an example of what I'm talking about.
1024x768 - cpu is pushing 100fps, 8800gtx is pushing
200fps
1280x1024 - cpu - 100fps, 8800gtx -
150fps
16x12 - cpu - 100fps, 8800gtx -
100fps
2048x1536 - cpu - 100fps, 8800gtx -
50fps
Now here's why oc'ing the cpu at lower res gives perf increase. The game can only go as fast as the slowest part. So example 1 goes 100fps, 2 goes 100fps, 3 goes 100fps, 4 goes 50fps(the gpu has now become the bottleneck).
OC the cpu 100% and now you can change the cpu to 200fps. Which would make example 1 200fps, 2 150fps(the gpu is now the bottleneck), 3 100fps, 4 50fps.
So to sum it up, there are x(cpu) and y(gpu) frames. x = 40fps and y = 50fps game = 40fps
So yes a faster cpu helps no doubt because during a game the fps are not at a constant rate, they are always in fluctuation depending on what the game engine needs atm. Alot of physics/AI/architecture in a scene can bring cpu perf down to 15-20fps while the gfx card is still able to push 100fps(ala oblivion in a city section). You can have a 9900gtz ultra and you are still only going to get 15-20fps because your cpu is holding the game down. This is the proper example of a cpu bottleneck. But go to the forest in oblivion and the cpu is pushing 100fps(because cpu load is now lighter) while the gpu is pushing 60(gpu load is heavier) and now you have a gpu bottleneck.
Very long post but I hope you take the time to read it. You'll have a better understanding of how a game engine uses the parts in your computer. Sometimes you are gpu bottlenecked, others cpu bottlenecked. With an 8800gtx, I'd say you are cpu bottlenecked 95% of the time in todays games unless you game at ultra high res(over 16x12).