Get some red nail polish and paint the line 200rpm to the left.
Think you are mistaking your rev limiter for tach redline.
If your engine is cutting out at the limiter, you aren't making max power. If you moved it to 6,400 rpm, you would lose power at 6,400 rpm and likely cause damage in the long run if you keep hitting it.
It is sort of like anti-lock brakes for your engine, it cuts spark or fuel and causes a fast rpm fluctuation, stressing pretty much anything that rotates or moves in your engine. Ok occassionally, but it sounds like you want to hit it all the time.
Might be time for a different vehicle. From your description, your engine will live a very short life.