Put a good cooler on that thing and pump those volts to 1.42v and go for it. Don't forget to bump your nb voltage a bit and make sure to increase your vTT.
As Enab states don't be afraid to push that vCore up. As for your nb, may or not help pushing it up slightly from what your "Auto" will set it at, but watch the nb Temps if you do, personally I didn't have much luck with lowering vCore by raising nb.
As for your vTT - Auto will set it at 1.3v which is plenty for a 1800 FSB, no need to go to 1.4v. Some folks are schieving thier OC's with vTT set to 1.2v by making adjustments to their GTLREF Lanes, however the process, from what I read is quite long and drawn out to find the optimal xx mV to set the Lanes at....default is "Auto"
Introducing me n my OCD to Watercooling, is like taking an Alcoholic to an "all you can drink" Beach Bar in Mexico