Can you swap a GPZ750 or KZ1000 engine to a 750LTD

I have a 1981 Kz 750 LTD with a shot top end.

After trolling craigslist, I've found a nice engine from a 1983 GPZ 750 with carbs, and another good looking engine from a 1981 KZ1000 with carbs but no starter.

My question is, could I do a straight swap of my complete engine for either of the two, and, failing that, could I swap the top end off the GPZ for the top end off of mine?

I'm a student on a budget and I appreciate any input! Thanks!

the kz 750 and the gpz engine are baically the same. HOw shot is the top end cause you could bore it out to an 810. What year gpz engine are you looking at? the 82 isn't much of an improvement over the kz. I don't know if the 100 will fit. I believ you can make it fit.