fitment of early GPZ750 tank/tail/side covers on kz750

I recently acquired a 1981 KZ750E, can a 1982 gpz750 or 1983 kz750 tank/tail/side covers fit on the 1981 kz750E without modification? are the frames and mount points the same across? thanks.

Frames tend to vary. it depends.
You could compare the diagrams at Kawasaki.com or Partzilla. the drawings are fairly accurate.  Partzilla is easier to use. 
The 82 750-R1 body parts are different.  I'd guess an R1 or L3 tank might work if you bend the rear mounting tab, but that is just a guess. 

ps:  are you just trying to make cosmetic changes or do you need parts?

From what I know, the tank have different rear mounting, and tail piece have different mounting as well so no, they won't fit without modification. Not sure about the side cover as I never wanted to replace mine (which is 82 GPz/KZ 750) so never look into it.

www.kzrider.com/forum/11-projects/606825...kz750-gpz-r1-project

You can reference the above site. My resurrection project and you can see the side cover and tail section.