not sure about that but i have a 5200+ just sitting hear as a paper wait that i would give to you it has the heat sink and all in fact i have an 965 heatsink that would do even better if you wish to over clock the 5200 just a though it has been sitting here for a bit it is in the box still but it is not a black edition. email me if you want it firstname.lastname@example.org
look, i used to have an athlon64. they are difficult to overclock. I had to drop the HT speed and drop the ram speed bump up the voltage and still didnt get much from my 3500+ (2.2 - 2.5 ghz is all i could achieve). You dont gain much from those cpu's anyway. If you can get a bit of money together you could buy a second hand core2 duo and motherboard real cheap which would give much better performance than your current setup.
@im2thecrowe: That's completely true that a C2D build would outperform it. But...
...a lot of AM2 boards can handle AM3's as drop-in replacements. This is often your most cost effective option. Check the motherboard manufacturer website and see if your board has AM3 compatibility. You'll still have to adhere to max CPU wattage (95W or 125W typically), but it's the cheapest upgrade path if it's compatible.
Even if compatibility isn't listed (such is the case with Abit mobos), it doesn't mean it's not compatible. If possible, find a friend who will let you test their AM3 after you do some research.