You can change your timings, my 3-3-3-8 RAM could run at 2.5-3-3-7 but it recommended running it at PC2700 speeds instead of PC3200 if I did that. You'll get more stability using better RAM as I've found out. That kingston value ram musta been holding me back because getting my computer stable was a *****...now that I've put in this 256mb Samsung it's stable as hell at 2.7GHz.
Each number in ram timing represents a clock cycle which is measured in nanoseconds. When you loosen your RAM timings and put in more voltage you're giving it 'breathing' room because if you are overclocking the RAM then you will need to loosen up the timings and feed it more voltage so the RAM can work at those overclocked speeds. If you aren't going above 200FSB on PC3200 RAM then it's not being overclocked and there's no point in chancing them
However, at this point I feel I'm just going to save a little more and invest in the XMS series because I need the stability, and I couldn't get that out of kingston value ram then I'm going to try some Corsair High performance XMS 2-3-3-6 (1T) timing ram and hopefully my system will be completely stable
Being at 2.7GHz is pretty nice, but I need the RAM power also so for the moment this PC2700 is cuttin it. But 2.7GHz on air is a pretty dern good OC according to most forums I've read...especially on air with a full load temp of 45C...so hell I might even be able to push 2.8 but I don't know yet
EDIT: I tried 2.8GHz but I couldn't even get it to post, guess I need watercooling or something along those lines for that even though my temps aren't even that hot right now....I might try a little later and add in a lot Vcore and see if I can get it, but overall I'm going to be pretty happy with 2.7GHz