My opinion is its not worth it but I know some others will disagree. My point of view is you are forcing the hardware to work harder than they were designed to and therefore you at least shorten their life and of course if you go too far its bye bye time. And I simply cannot afford a new PC if things did go wrong.
If you really are serious about this and knowing the risks wish to go ahead then fine thats your choice. I suggest looking here as an example click here or here click here lots of advice on both the sites.