32002-1912 will fit:
Kawasaki Motorcycle 1987 KX250
Kawasaki Motorcycle 1987 KX500
When looking up parts interchange I use
https://www.partzilla.com/ most often.
Go there and make a account and you will see prices as well as interchange info.
The sub frame will fit:
Kawasaki Motorcycle 1987 KX125
Kawasaki Motorcycle 1987 KX250
Kawasaki Motorcycle 1987 KX500
Besides interchange, my site has parts info not available on normal interchange sites..
http://www.oem-cycle.com/KAWASAKIKX500BIKEID.shtml