if your CPU is bottlenecking your GPU , it will help
if not , you will see very little difference
any way you will get only aroud 5-10 fps boost max with realy good OCs ,which is very hard to get(plus you need a lot of skill+luck on your k series CPU)
And think if trading your life of your comps. for a few FPS is worth it
PS- your specs would help
Ocing GPU generally helps better than the cpu