It really depends on your Q6600, some will do it on the stock volts, some require a bump up to around 1.3v ish. Just test it with Prime95 and see if it is stable, if not, increase the vcore a little and test again. It's a long process but once it is stable then your done. You shouldn't have to touch the VTT at all. But be aware that too much volts can be as unstable as too little.
I was lucky and my Q6600 only takes around 1.39vcore and 2.11VTT for 3.6ghz.
I aint had any experience with your mobo, so would be able to say what volts you would need. Just google it and see what other have done with a similar set up to yours.