If there's nothing wrong with your setup then you don't need to do anything to it.
Shortstroking means the piston is not pulled back as far before being released, which in theory reduces FPS and increases the ceiling for RPS before hitting premature engagement with a specific weight of piston. Because the piston is released sooner in the cycle, there is more time for it to return home.
If you are at the edge of premature engagement (the point which is usually discovered by destroying a piston prior) you can SS to make it cycle reliably. If you need to drop FPS but do not have or want to mess with different springs or inner barrels, you can SS to do so.
If you SS your current gearset without changing anything else, the only thing that will happen is your FPS will drop.