Rob, if for whatever reason you feel like it's still pulling hard at 6K, you can always throw in the 6200 chip. I have some video of me smoking a burnout in a lineup after a car show and it's really hard to burn out my car in 1st...I'm just immediately at the rev limiter. A comment on the video got me thinking. As it bounced off the limiter, a guy in the background says "loaded up!"
And it did sound like that. There was clearly further to go. I put on the 6300 chip, and literally...that's how much further it had to go. When it hits the limiter at 6300 there is no doubt that there isn't a whole lot of power yet to be had. Dual plane intake, hydraulic cam/lifters...just no sense in it.
Play around, have fun, but recognize your motor's limits. Not necessarily it's "blow up" limits...but its power limits. Only thing you gain revving it up way past the power peak is wear and tear. But it is nice to hone in within 100 RPM of the ideal full throttle shift point. And when they start spinning north of 6 grand, they do sound NICE!!
Enjoy!!
JP