Magazine 
Date 
Article Title 
Author 
Synopsis 
Rider 
Aug 1980
Testing a 
Kawasaki KZ550 
Alan Tratner
not yet
Motor Cyclist
Feb 1981
750's beware here comes the GPZ550
Ken Vreeke
The article mentions the KZ550 and parts interchangeability.
Thank's to Bill Meilahn for sending in a scanned copy of the above article.
I have provided a low res. version where each file is about 400k.
Page1 Page2 Page3 Page4 Page5 Page6 Page7 Page8 Page9
Rider 
Apr 1982
Sport touring on a Kawasaki GPz550H 
Rich Cox
not yet
Cycle Guide 
Jun 1983
Suzuki GS550E 
vs 
Kawasaki GPz550 
Charles Everitt
not yet
Cycle Guide 
Jul 1984
Middleweight Title Fight 
Larry Works
not yet
Cycle Guide 
Mar 1985
Kawasaki GPz550 
 Kawasaki Ninja 600R 
Paul Van Zuyle
not yet
Motorcyclist 
Nov 1992
81 Kawasaki GPz550 
 92 CBR600 F2 
Dexter Ford
A thank you goes to Duane Wiebe who sent me the scans
article
Motorcyclist 
Feb 1993
Best under $1500 
 GPz550  RZ350  XJ650R
not known
A thank you goes to MLK who sent me the scans This link opens a PDF file
article
Classic & 
Motorcycle Mechanics 
Apr 1997
Kawasaki 
GPz550 Projuct 
Graham Curtis  dealing with rebuilding an 81 GPz550   Part 1 - Mar '97   Part 2 - Apr '97   Part 3 - May '97   Part 4 - Jun '97   Part 5 - Jul '97   Part 6 - Aug '97   Part 7 - Sep '97   Part 8 - Oct '97   Part 9 - Nov '97   Part 10 - Dec '97   Part 11 - Jan '98   Part 12 - Feb '98   Part 13 - Mar '98   Part 14 - Apr '98   GPz Model Guide - June 97 - Page1 Page2 Page3

Thanks to Mike Corcoran for scanning and sending these.