The Kawi has 17 more hp than our little GS500's, and it only weighs 15 pounds more. Mabye the Kawi has longer gearing?

According to the suzuki website and the kawasaki website, the ninja has a dry weight of 388, and the gs 396.8.. so the GS is 7lbs heavier.. neither website posts an HP number, and I'm too tired/lazy/mostly tired to google it..

Their real-world dry weights are 372 and 388.  That doesn't account for wet weights which include the EX's slightly higher fuel capacity and rider weight and such.

most the power from a stock GS is developed around 9krpm, and a sharp fall off arund 10.5.   when falicon ballences a GS crank to run without the counterballencer its for 9krpms,   think even the megacycle camsfor stock pistons and springs peaks around 9-10k  need the racers to chime in.  the power band can be moved up or down but i think redline is that safety zone just before things start considering leaving the confines of thier designated rolls

The redline on these motors is designated by the crank.  It's the same as the EX500.  These old-tech parallel twins are literally trying to tear themselves apart and a little after 11k is where the crank starts walking and vibration starts tearing other things apart.  The general design of the motor doesn't make much power at those speeds so the necessity of revving that high is non-existant.