Overclocking the E5400 help?

[thegameplayer]

What is the highest i can achieve without instability or too much heat if i oc the E5400 2.7 ghz on the Gigabyte GA EP43 UD3L motherboard with stock fan?

 

[Fetal]

near 3.5

 

[shubham1401]

^+1. But watch the temps