Overclocking an E8400 with stock cooling

Hi i want to overclock my cpu, since in some games (GTA4) it is bottlenecking my performance. however i only have a stock cooler and would rather not have to buy a new fan. if i have to get one i would appreciate opinions on the best cpu coolers. another possible problem is that i only have a 650w power supply and a large portion of that powers my 4870x2. i still want to keep the stability of my current system. how far do you think i could OC it with out any negative effects?

thanks,

V3NOM, stop changing your avatar your confusing me, I'm a simple man.

OP, if you have the clearance in your case, then do yourself a favor and install the XIGMATEK HDT-S1283 120mm Rifle CPU Cooler with the XIGMATEK ACK-I7751 Retention Bracket. I've installed two and they really are that good.

Note:
When applying thermal paste with the Xigmatek cooler, apply a thin layer across the CPU IHS (top) or across the whole base of the heatsink. The paste won't spread properly through contact because of the gaps between the heatpipes and the base.

I changed the color... subterfuge.

I don't even remember what it was, I just remember I recognized it, and it was changing.

[Cleaned]

Maybe I'll change mine for the new year, probably not, it's too complicated.

Good luck with that, you'll need it.

This isn't the Other.