I expect it will be fine, but it depends on the specific unit - a high quality unit will have no issues running close to capacity, while a low quality unit may deliver dirty power even at low load.
Some years back I had a heavily overclocked Q6600 (105w TDP) and a pair of OC'd HD4870's (160w TDP x2) running off of a Fortron 460w power supply. It was one of the better units of the day, and ran for 6 or 7 years before I parted out the machine and upgraded everything. By comparison your CPU has a 91w TDP and your GPU, 150w. Your motherboard and RAM are probably a lot less power hungry than the older DDR2 and 775 board I was using.
Another point of reference, the system in my signature draws about 160w at the wall under torture testing with a mild OC - about 4ghz on the CPU and a slight GPU clock bump. If we assume 85% PSU efficiency, that's only maybe 135-140w that the power supply has to supply, making the 400w unit I have massive overkill for even an OC'd i5 and 1050 Ti.