I have a 3200+ Newcastle CG. I got it to 2.4ghz no problem on stock voltages. I am not running it that way though because full load I got to 62C... I didn't like that one bit. I may reseat the heatsink (Thermaltake Venus 7+) to see if it helps. Stock, it is running about 55C full load.
Before that, I had a 2800+ CO. I think it was a Clawhammer, but CPU-Z said Newcastle. That topped out at around 2.2ghz with 1.7V, and ran about 55C. I won't go past that voltage.