Yet another Q6600 Overclock Help

I could use help overclocking my computer.(obviously) I have a q6600 g0 stepping, that has a really low stock voltage, I think the board sets it auto to 1.235v, which reads as 1.056 in cpu-z. That is fully stable at 2.4Ghz on my gigabyte EP43T-UD3L. I was very easily able to get it up to 2.96 GHz, but it seems impossible to get at 3Ghz, or higher. I tried everywhere from 3.0-3.35 Ghz since I have heard of stability holes around that area. I am using Crucial DDR3 1333. (2x2Gb) I dont think I need any faster, especially since i would drop the memory multiplier down and it would still not be stable. I am afraid to boost the voltage too high, as this pc (my first ever build) has to last me some time.
With such a low stock VCore, I would think this chip would be very receptive to OCing, and will run at 2.96GHz @ 2.2375v (BIOS) that reads at 1.1875v or so in cpu-z. I have boosted the VCore all the way up to 1.3250V and could not manage a mere 40 Mhz more. Is that normal? I have an AZZA Spartan case with a custom sidepanel for high airflow and 2x92mm fans that blow a total of about 90cfm directly onto my CPU heatsink (Zalman 9500) and two extraction fans and rear vents. Yet, I could not raise my VCore any higher becuase I was getting 79C in IBT and 75C in Prime. I dont think I should go much higher if at all.
I have an obsessive personality and have been reading about almost every other q6600 I can find and overclocking in general, but I still cant get this. Like I said earlier, this is my first build, and I did it on limited money, but Im pretty damn proud of it. I don't know any other 17 year olds who can do this, but I want help from all of you to make this the best it can be. Thanks!