Will this GPU work in my build?

Yes, but a 550W PSU is pretty marginal if you're overclocking both the CPU and GPU.
 
If you didnt buy the parts yet, I recommend cutting back on the GPU to something like a 770 and upgrade your PSU to a 650W or a better case or even an SSD. It is your choice though. If you play at 1080P, the 780 is overkill.
 
Seeing as the GPU is listed as "will be replaced", I'd assume the PC has already been built. I do agree with both you and slh28 though.

I saw that and that is what I thought. I thought when he said "build", he meant that he still has to order. I read it again and I noticed that I misinterpretted it.
 
Back