Not sure what's going on, maybe your carb is smaller than mine, I don't know. I think I was running 7 to 7.5g sliders in mine, worked great, but I was running 108 main jet. Don't know what you weigh, but I am approx 175 to 180#'s. Also, I was running Malossi variator, which seems to help keep revs up, compared to OEM.
I looked at the linked comparison chart, and until you get past 7500 revs, you will have no improvement. Bigger carb, better pipe is all about making more revs.
Try the lighter rollers, I tried 5g in mine once and it rev'd to the moon, should get you to the powerband. Let us know, good luck. Cheers