Choosing Motherboard for FSB Overclock

Hopefully one of you more experience overclockers can give me some reccomendations as to how to determine if my board is the limit for overclocking my CPU or if its my processor reaching its limit.

I'm running at 250fsb * 14multiplier giving me a 3.5GHz overclock from a 2.8GHz on my Phenom II x4 830. I cannot increase my FSB past 254 without causing a failure on restart. My motherboard is a M5A78L-M LX. If anyone could give me some instructions to help determine how to increase my FSB I would be very thankfull.

In the case that my Motherboard is the bottleneck in increacing my FSB; what should I look for in a motherboard for FSB overclocking? Higher Phase values? Larger onboard heatsinks? Better powersupply input? Is there a voltage control hidden in the bios?

PS: This has been edited twice now, after reading it I saw how poorly I had written my first post.

I think you did hit the limit of the CPU itself (did read about 3.6GHz on that CPU, but i doubt it is really stable). If you really need more performance, you should wait and use what you have, save some $, and latter upgrade CPU and Motherboard with better platform. I'm not overclocker, but i can't imagine that anything above 3.6GHz on that CPU will be beneficial.

yeah probably the cpu is at his limmit, also the mobo, that mobo is an older  board. if you realy wanne go at high overclocks  i think then a decent 990FX chipset board would do a better job. like the Asus M5A99Fx pro R2.0 with 6+2 powerphase. or a Sabertooth with 8+2 powerphase, but then i still think you won´t get much higher as you allready have, your cpu is probably at his limmit too. i would personaly recommend if you are a diehard overclocker, to go with a sabertooth and FX8350 combo. with decent cooling should be able to go over 5GHZ