getting back in the game

So I've been out of water cooling for a while. But my x1900gt gets quite hot, and even hotter now that it's starting to warm up outside. So I have a maze4 block with a mag3 pump and my newly acquired BIPII. The trouble is my case; it is tiny. I have limited options for pump and rad placement. I've decided that I'm going to put the rad on top of the case on the outside and run the tubing through the metal. But my pump is a little more difficult to solve. I was thinking about moving my two HDDs up to the top of the 3.5" drive rack right on top of each other. But that makes me worried. Is it really a problem stuffing two HDDs right on top of each other? I see heat being a problem and maybe even the cicuit boards shorting on the case of the other HDD. But this seems to be my only option. I will post pics of my case once I get home.

You could always mount one or both drives in a 5.25 bay (that is assuming you have any free). I personally would not stack HDs on top of each other like that.

You might have a spot where you can mount one HD vertically on the case wall. This can be better than the usual horizontal drive bay mounts because natural convection is more effective in this position.