For future reference, use PERCENTAGES or state the original FPS since "7-8 fps" has no meaning otherwise. If you had 8FPS that could be double. If you had 100FPS it's only 8%.
But yes, overclocking the GT1030 is far from pointless. In fact, with a good fan you may go from a set max of 1600MHz up to 2000MHz. The max turbo boost value is usually exceeded in practice (i.e. 1500MHz set but 1600MHz in practice with sufficient cooling) but overclocking simply raises the ceiling.
So assuming 270MHz over say 1700MHz max then that's a 16% higher frequency on the GPU.
Assuming you also got that scaled in the game then it would translate from roughly 50FPS to 58FPS... am I close?
*So I don't have a GT1030 but I do understand NVidia Turbo...