as someone mentioned - it all depends on the age of the cpu and luck. try not to go past 60c, 1.45v is usually a good place to start. avoid passing 1100 on the ht by dropping multi. going below 1K dont hurt performance tho.
i would try 11*250 @1.45v with 4x htt multi and ram on 333 setting as this should give everything stock speed except cpu/mobo and a nice frequency of 2750 and is well within grasp of most recent chips. then work up in 5mhz steps. if its not stable and temps good, try upto 1.55v on the cpu. still no good, drop to 245.. 240 235, and so on. when you have the cpu speed limit found you can sort the ram speeds.
lock the pcie/pci bus.
i would try 11*250 @1.45v with 4x htt multi and ram on 333 setting as this should give everything stock speed except cpu/mobo and a nice frequency of 2750 and is well within grasp of most recent chips. then work up in 5mhz steps. if its not stable and temps good, try upto 1.55v on the cpu. still no good, drop to 245.. 240 235, and so on. when you have the cpu speed limit found you can sort the ram speeds.
lock the pcie/pci bus.