Old Car and Bike rambling

Over the winter I changed the Master Cylinder, added dual piston calipers with EBC HH pads, cb900 cams and CBR Coils. I probably should have taken her out for a ride sooner or rode her around for atleast 2 seasons before making the upgrades because my memory is not so good and can't really provide a reliable seat-of-the-pants feel before and after. The bike revs effortlessly now and brake modulation feels very nice. The cb900 cams are in, but I can't remember how slow the bike was last year. She scares the heck out of me now in the 6-8k rpm range and I'm pretty sure I only hit that range once or twice in my local around town riding last year so not really much to compare and remember. It definitely feels different now though because it gets up to 5k rpm so much easier than last year. Unfortunately I'm noticing a new sound around 5.2k rpm, not sure if it's a baffle or something else is loose, but I can hear a rattle or vibration out of the exhaust when I rev it in th