the I5-760 is roughly half as powerful as my I5-3570k. At 60fps, max settings, my CPU is 80-90% most of the time. I usually have it o/c to 4.4GHz, so it's around 60-80% usage.
You may not get a constant 60fps with a single GTX770 anyway (might be ok with no MSAA), but I recon your CPU may limit the FPS to around 40fps or less.