First, Yes it can be overclocked as most anything can, but to what extent is the real question. Overclocking is limited by the ability of your BIOS/Motherboard, CPU, RAM, PSU, and heat managment. The best way to figure out these limits is to try, move slowly up until you get system errors, failure to boot, or too much heat to safely run at those settings 24/7.
I cannot research your parts and how well they OC or how to overclock them best, as it is a time consuming hobbie to do so, and takes alot of effort. I can point you in the right direction to a few guides on overclocking and maybe this will give you some information to accomplish what you want on your own.
After reading up on these and maybe google a few other Overclocking guides in general and maybe even trying a light OC on your PC, then come back with that knowledge you gained and parts that you really need help with and I am sure someone here at THW can help you on your way.
I hope these links help you out and good luck OC'ing, it can be alot of fun but it takes time and research to get you feet wet.
I've got the same MB and processor that I use as a Folding rig now. The MB is very capable overclocker, I've had mine over 525 FSB and it didn't complain too much, but that wasn't for 24/7 use of-course. The E8400 doesn't put out a lot of heat like an i7 but you still need a decent CPU cooler to keep it happy. The RAM is what will hold you back unless you have some very good OCing RAM. Even just to 4.0 Ghz you will have to OC your RAM to 890 so I would look at how far your RAM can go first, then work on the CPU OC. Have fun.