it might be worth seeing where your optimal shift point is
and if it turns out that is well below where this racket starts I would not even worry about it
I agree always use recommended springs and retainers. Any time you reach max horse power like 5500-5800 it time to grab another gear not to keep reving it just because it will.
Many smart-phones have an accellerometer chip in them,, so if you download a G-Meter app.. you can find your shift points by taping your cel/g-meter beside your tach,, and note when you start to loose power,, a coupla hundred rpm below that is shift point,, or you could go buy a g-meter...