Here is some K5 info I have collected on the forks:
USD – KYB – X125-R X125-L - CHROME OD 43MM - C/L 37.25" - BLUE - UPPER 51.9MM - LOWER 56.6MM - BRAKE MOUNT C/L 61MM – AXLE CLAMP ID 22MM FORK SEAL 43MM X 55MM X 9.5/10.5/11 1991 KX500
USD - CHROME OD 43MM - C/L 37.25" - BLUE - UPPER 51.9MM - LOWER 56.6MM - BRAKE MOUNT C/L 61MM FORK SEAL 43MM X 55MM X 9.5/10.5/11 1992 KX500
USD - CHROME OD 43MM - C/L 37.25" - BLUE - UPPER 51.9MM - LOWER 56.6MM - BRAKE MOUNT C/L 61MM FORK SEAL 43MM X 55MM X 9.5/10.5/11 1993 KX500
KYB KX94L KX94R - CHROME OD 43MM - C/L 37.25" - UPPER 51.9MM - LOWER 56.6MM - BRAKE CALIPER C/L 102MM FORK SEAL 43MM X 55MM X 9.5/10.5/11 1994 KX500
KYB KX94L KX94R - CHROME OD 43MM - C/L 37.25" - UPPER 51.9MM - LOWER 56.6MM - BRAKE CALIPER C/L 102MM FORK SEAL 43MM X 55MM X 9.5/10.5/11 1995 KX500
CHROME OD 43MM C/L 37.25" - FITS 96 KX500 FORK SEAL 43MM X 55MM X 9.5/10.5/11 1996 KX500
USD - KYB - KX94-L KX94-R - CHROME OD 46MM - C/L 37.25" - UPPER 53.8MM - LOWER 58.9MM - BRAKE CALIPER C/L 102MM - FITS 97-02 KX500 FORK SEALS 46MM X 58MM X 10.5
CHROME OD 46MM C/L 37.25" - UPPER 53.8MM - LOWER 58.9MM - BRAKE CALIPER C/L 102MM - FITS 03-04 KX500 FORK SEALS 46MM X 58MM X 10.5
You can find it here:
http://www.oem-cycle.com/KAWASAKIKX500BIKEID.shtml