Do not increase the voltage.
Leave it at stock or even decrease it, while increasing the FSB.
You should be able to reac at least 3.3GHZ at 1.4 voltage.
Stock settings are FSB 200 = 2.7ghz
Normal Cpu Vcore 1.4v
Normal Cpu Vcore NB 1.15v
so i should just leave these at stock right, i dont plan on getting more than 3.5ghz