Hi,
I'm new to watercooling myself, however I think just those two relatively small rads might struggle to effectively cool your setup.
I'm running a 2500k @4.6 and a pair of GTX 570's myself, Antec Kuhler for the 2500k and stock air for the 570's, and was told that a 2x 240mm rad setup on mine (CM 690 II Lite) isn't really enough cooling. I was advised that an external rad would do the job, but wouldn't be as tidy as an internal build.
Like I say I'm fairly new to watercooling, having only helped a friend build his loop using an external rad, hopefully owner of 650d here can provide better advice.
Best of luck.
Scoob.