I achieved 154mhz FSB using the asus default of 3.56vIO. I also tried it at 3.3vIO with no differance. The vCORE for me makes no differance in the FSB speed I can run, however I vary it up to 2.2v for overclocking. I can achieve these FSB speeds at about 1600 using as low as 1.6vCORE on my 1.4g AYHJA Athlon "Y", and up to 1500 at 1.6v when I still had my 1.33g AXIA Athlon "K".
In my opinion your bottleneck would likely be the memory, or a card. I did a little research on your board, and users are regularily going up to 160mhz FSB with stock cooling on the board. Try removing all the cards except video, and try each of your sticks of ram in varying slots and one at a time set to Cas3. Cas2 is better, but it might help you discover a bottleneck, as usually ram will clock higher set to cas3. As for moving the ram in different slots, I've heard guy's finding one slot works better than another and each stick is usually different (even if rated the same). I've heard of many people using PC150 Cas2 ram and finding out it won't do 150 at cas2, so keep open minded.
If you know anyone with a real fast system, maybe swap your cards and ram and see if they will all run fast enough, although again in the end sometimes certain cards just "don't like" certain computers.
Welcome to overclocking! Overturn every rock, even when you know what's under! Good Luck
