To find the "Best" clock settings, do the following:
Increase your FSB by 2-3 Mhz until it either refuses to boot.(Either Windows Blue Screen, or it just won't boot)
IF it doesn't boot, restart your PC, get into the bios again, and drop your FSB by 2Mhz.
Run some form of Memory Benchmark program.
Record your score.
Increase your CAS latency by .5(Or the minimal) and continue to increase your FSB. Repeat process until your memory scores are LOWER than the last memory scores you got. IF they are lower, drop your latency to the last speed where it could boot with your RAM at the lower CAS Latency.
This will give you the best RAM performance. Good luck!