i highly doubt you will succeed. i have not heard of a single 1gb stick that can run at 2-2-2-5 latencies. be happy with 2-3-2-5 that is about as good as it comes
i have the OCZ Titanium 2.5-3-2-5. i loosen it to 3-3-3-8 and OC'd more. no speed difference in everest RAM bench test. so i dought you'll see any difference if you can even manage to make it happen.