Something like this should not be too bad for your system, just check the specs and make sure you’ll have enough room in the case for it.
http://www.newegg.com/Product/Product.aspx?Item=N82E16835103047

I have a q6600 and i’m only using an Arctic Cooling Pro 7 heatsink, its very basic and not really designed for overclocking which i have not bothered with and even under a 100% load render for several hours, my cpu wont rise above 55C.

Even for stock, 74C just seems way too high to me. Correct me if i’m wrong. What temp does your cpu idle at?

Also, add an exhaust case cooling fan if you don’t have any. In most cases its a good idea to have intake and exhaust case fans so you have proper airway circulation within the case.

It’s not too bad in idle I think, about 38 C. My case has 2x 120 mm fan. case temp is quite low like 29 C

----------------------------
http://www.yvgrafix.com

AMD Phenom II X4 965
4gig Corsair 800Mhz 4-4-4-12
nVidia GeForce 470 GTX
Asus m3a78-t
Windows 7 x64
Velociraptor
2x 250gig - Raid 1

then you’re right its definitely the cpu cooling. my cpu idle runs at 43-46C and 55C max under load, that just shows how effective the cooling is. I would go for the upgrade, it would be worth it in your case.