Custom ground camshaft, low power

I just read a bunch of info on solid lifter cams and think I might be up for it. The xs282s thats been mentioned says its rpm range is 2500 - 6500. Right now I make peak power at 5500 and have a rev limiter set at 6000. Would I be safe reving my motor to 6500?
Another question. Why do almost all calamity have more lift/duration on the exhulaust side? Isn't the intake more important. Id think it would need to be the same or bigger on the intake. Id like to get as much lift as I can fit. Particularly on the intake.