Then your perfectly Ok. What cooler are you using? Those temps are very good. Still, i have seen people get to 4.0 Ghz at and under 1.125 v(only if i could find the link). You could go to maybe 4.5-4.8 Ghz and depending on your temps, maybe even more.
BTW I found a thread where the user stated he got to 4.5 Ghz at 1.155 v and his temps were dat 73° C at full load and 69° C average. What's your cooler?