I am upgrading to a new GPU soon, it will be an EVGA GTX 670 FTW edition.
I currently have an intel i5 3570k processor, not overclocked at all. I am wondering if this card will bottleneck my processor, since I see a lot of CPU usage when running games at 1920x1080 at 30fps.
A card would never bottleneck a CPU, it's almost always the other way around. You'll be fine, trust me, but why buy a k series chip if you are not planning to overclock? Just get like an i5 3450/3470 instead, the performance will be relatively the same at stock speeds.