Ive previously been at over 170 mhz with a Epox kha+ and it was very stable except in games which caused it to lock up. ( and im not much of a game player, so it was no big problem

)
In this situation it was not actually the memory which held me back but my sound card stangely enough, I had to remove it to exceed 160 mhz FSB.
A lot of people hit around 170+ mhz with Crucial and big voltage on the Kha+ as well a while back, however my choice was Kingmax