Depends on the fan speed and type. There is a sweet spot for most radiators, around 1500 rpm. Above that fans work better in a push (fan-rad-case). Below that, fans work better (especially higher cfm fans) in a pull configure (rad-fan-case).
Most stock fans that come with CLC's are rated 1400-2000 rpm, so are advised to use the fan in push. If the fan is a lower static pressure, however, pull is better.
I use a h-55 as my exhaust, mounted top, and do not usr a rear exhaust at all. For CLC's this is actually a better decision, as heat will naturally rise, and a top exhaust works to just help that, whereas a rear exhaust is trying to pull the heat 90 degrees, disrupting the natural airflow.
All that said, with a decent fan, with your CLC, you are pretty much good to put it anywhere you can, what pleases you aesthetically, in any config works for you.