if you plan to get far, start with an aftermarket cooler (the hyper 212 evo is ~$30)
once you get that, try a fsb of 257/258, try to keep the NB/HT/RAM speeds as close to stock as possible, enable LLC (load line calibration) if it's available on your motherboard, and a VCore of 1.45V (approx, may differ for you)... if you dont have LLC i would try in the low 1.5V's
have you tried unlocking the fourth core?