My opinion would be that u should place the pump between the 140mm radiator and ur Dual 200mm.. I'm not very experienced on water cooling systems but ur pump should be relatively close to the CPU and GPU in the circuit so that the water will be entering the blocks with turbulance, for increased cooling effects since u're O.Cing up to 4.0 GHz..Have u calculated the flow rate of ur system(GPM)?? Whatsoever, any other more experienced member could correct me where I'm wrong