Dang..2x 4x120 rads? What kind are they? Slims, but you are looking at close to 700+ watts, potentially for each? That's some significant over-radding right there. I like it.
What are you running for blocks and pump?
For those temps, you shouldn't be seeing that, I wouldn't think. Do you have air anywhere (rads)? Good flow? How are you flowing your GPUs...serial or parallel and what blocks? Should be ok either way, but just curious.
What did you use for standoffs for the rads?
(Looks a LOT like my previous setup, but I was running dual MRC320's)