RobCrezz :
It may work, but its cutting it very close. I would suggest buying the 750 ti instead, as it uses significantly less power and performs better.
GeForce GTX 750ti - 20A and a 400W PSU minimum
GeForce GTX 750 - 20A and a 400W PSU minimum
GeForce GT 740 - 20A and a 400W PSU minimum
GeForce GT 730 - 20A and a 300W PSU minimum
So getting any of the GTX 750 on a 320W PSU is more of a gamble rather than a clean solution. The only card that works is GT 730 for that PSU.