Radiator Position
 

Where is the best place to posotion a radiator inside the case?

Where ever it fits best as long as the heat is being removed from the case. Although if you have a low output pump, air may get trapped inside the rad if it is mounted above other components.

could i position it in front of the rear case fans?

Depending on the heat your moving putting it on intake fans will give cooler water/hotter case, and putting it on the exhaust will give cooler case/hotter water. I don't know how noticeable this change is though. From everything I have heard it seems the best way is to have fans sucking air over the rad not blowing. My system when I finnish it will have two rads, one on exhaust to cool water down some, then another on the intake to get it closer to ambient. With the pump in between.
Edward

Crosstrack,

Do you mean using the rear fans to draw air through the rad? I assume these are exhaust fans.

If so that should be OK. Although the water will only get as cool as the inside of your case. So remember to keep the air moving with some other fans.

you can place it in the front of your case with a duct so the hot air of your case dosent effect your radiator temps

Thanks for the great advice guys