Sounds interesting and I'm sure would be great for overclocking but on air I've hit 3.6ghz overclocked on my Core2Quad Q6600 and don't even think the processor can handle anything beyond that.
I lapped my heatsink as well and dropped 8c.
Getting liquid cooling I think would be more of a waste of money at this point considering the amount spent on air cooling already.
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Inferno Package/CAI/180tstat/3" DP/AL 104 XP's/3.8 MPS/Tuned