Will radiator positioning effect flow rate and head?

The main question is posted in the title, but here is a little more information:

I'm going to externally mount my radiator (its a 3x120mm, most likely a black ice) but I can't decide where to put it. I'm considering either the back of my tower or put it on its own separate platform. Note that the res and pump will also be external.

My biggest concern is placing the radiator in a place that doesn't require a lot of tubing (trying to reduce head loss) or in a position that will lower the pump's head. Maybe I'm over-thinking the design, but wouldn't a radiator in the vertical position cause a lot of head loss, since the water flow would need to go up the tubing, into the radiator, back up the radiator, then go through all the exit tubing? I assume that the best flow rates would come from a radiator that is laying flat, or on its side.... but maybe I'm wrong.

Any suggestions or knowledge to share?

Hmm. The positiong of the rad really doesn't matter. It's enclosed.

What does matter is the height of the rad from the pump, or any water components and the lenth of the tubing.

When putting stiff inside, top, back etc on a case, it's not far enough away or too high to matter.

Go for it, do it anyway you want.

Vertical displacement from the pump was something I put into consideration. Looks like I'll be putting it on its side, mounted on its own little platform where the pump can also sit.

Conumdrum, thanks for the speedy and informative response.

In a closed loop there is no "height" inside the loop, if that's what you're asking about. There may be other reasons to not put a rad above the rest of the loop, though I've done it more than once, but height - as in pump head - isn't one of them ...