The allendale cores don't overclock like the old E6400 conroes.
Still, though, you should be able to hit at least 3.2 with that voltage 8O I hit the same wall as you at stock volts, but I can hit 3.2 at about 1.375v. Then under load I ride the line at 60C with a Zalman CPS-7000.
The first thing you want to do is identify your "wall."
Reset your voltages to their defaults (Remember that the XMS2 RAM runs at 1.9, so crank that up 0.1v). 1.410 is definately on the high and dangerous side, especially if you're only getting 3GHz from it. Next turn down your CPU multiplier (yes, down). The goal here is is to stress your FSB/RAM without stressing your CPU (You don't want to go recklessly jacking up volts 'till something sticks).
The P965 and XMS2 should be able to handle a 1600MHz FSB with no problem, so you may as well start there (400MHz core clock). Run Orthos for a minute or two (more than that's usually unnecessary for testing the water. 99% of the time, if orthos throws an error, it'll happen right away).
Then start cranking up your core clock 3 or 5 MHz at a time (Keep in mind that your FSB will go up 4x your core). The P965 usually caps out somewhere around 1650MHz. If you want to OC above 1600MHz, grab a piece of paper and note where you hit your wall. Once you hit your first wall, you want to loosen up your RAM timings (go 5-5-5-15) before you increase voltages. The MHz gained with the overclocking will outweight any benefit of the timings. Then slowly increase the voltages for the RAM and MCH until you're stable. Mark the speed / voltages down on your piece of paper, rinse and repeat.
What you're doing is building a voltage/speed profile for your motherboard and RAM. Use speedfan to monitor your MCH temps. I wouldn't go over 0.2v over for the RAM and MCH. You don't really get that much more speed above 0.2 overvolts for the heat cost.
Once you know where your FSB/RAM maxes out, then you put your multi back up to 8x and core back to 375. Increase your core clock 5MHz per-boot (Yes, I know it's painful) and run Orthos for a couple minutes each time. Make sure you're setting your FSB/RAM volts per the profile you just built (You're usually OK stock until 400MHz core).
Only increase the voltage in small steps each time you increase the core clock 5MHz, because you want to get an idea of how much more voltage each 5MHz step takes for the CPU to be stable.
This process is slow, but you end up with only the minimal voltages for your OC, which means minimal heat and a maximum OC for your rig.
Just a couple more things:
1) Some chips have "Holes," where they just refuse to run at those speeds. It's good to have the OC profile for your FSB/RAM, so if your CPU refuses to go 3.0GHz ~ 3.2GHz, you can skip right to 3.4GHz with a FSB setup you know is stable. That way, if it doesn't work, you can be fairly certain it's just the CPU that won't go that high.
2) You might just have a chip that won't go that high. It happens :?
3) Whenever you're not sure about the temps a program is reporting, go back to the BIOS under "PC Health Status". Compare that number to what the program in Windows is reporting for idle temps, and you'll know which one is OK.
Good luck.