I'm glad to see you are getting things ironed out. Do you still have the regular intake? I'd be VERY interested and would bet the car would be a hair faster with the normal performer on there. If you were making peak power above 6000 and were shifting up around 6200+ I'd then think the RPM was the way to go. If nothing else, bump up your shift point next time out to 6200 and see what happens. Even though you are past your peak, you are still making good power as your graph doesn't drop off slightly. If you re-dyno it, I'd make some pulls to 6200 or so and see if it really drops off quick or not, this can also tell you if 6200 is too much, or possibly not enough.