You should be good. Plugging in those components into Martin's flow estimator, with a pair of Fuzion GFX blocks (worst case scenario), still comes up with an even 1gpm. So you'll probably be doing better than that.
i7 2600K | ASUS Maximus IV GENE-Z | 580GTX | Corsair DDR3-2133
With the mcp655 the flowrate should be slightly over 1GPM, but the fact that you have 2 rads means the coolant, although may be going slightly slow, will have a high Delta T between the input and output, so i think youl be golden.