Motorcycle Safety & Driveability: lower highway rpms, rear sprocket, great shape

Question
Ryan,
I have an 81 Kawasaki CSR 1000 that is in great shape.  The only problem I have is that the bike was geared to run at about 55 mph.  With speed limits being 70 mph on most highways, the bike running at too high rpms for my comfort.  I'd like to be running at about 3500 rpms at 70 mph rather than the 5500 rpms I'm turning at that speed at present.  My bike has a stock 39 tooth rear sprocket, and there was an edition that had a 42 tooth rear sprocket as well as one with a 37 tooth police edition.  Any suggestions?

Answer
Lox-
Well you know this is something that I am not to sharp on but I will give you my best answer anyways.  You know smaller engines in a sense are made to run at higher RPM's.  So somtimes if the engine is running at lower RPMs is can bog down.  The only thing I can suggest is like you said change the sprocket count on your bike.