i dont think you will be able to run the ram at that speed.
from what little reading i did (and i did it quick), it seems that it will top out a little below 220mhz.
loosening thr timings will slow the ram, but raising the cpu clock speed will speed up your ram, get it?
so, it's a trade off. for the most part, unless you are using a really ram intensive application it is better to get highest cpu clock speed possible. then worry about getting your ram up to its highest stable speed. or you can balance the two off.
for example, i run my ddr2 800xms at 430 something mhz when i have my normal overclock (about 2.6ish).
when i go to 2.8+ i drop the speed to ddr2 667...so that my ram is not overclocked higher than i like. it will do 450+, but i just don't run it that high.
as far as an explanation of ram timings i understand them, but explaining them is very tedious. google it or search here on the forums.
good luck!