Carburetor

Could I put a Kz1000 Carb on my Kz750?If so would I have to do any modifiying?

I believe the spacing is wider on the 1000 carbs.

What years/carbs are we comparing here? Both models came with different types/sizes of carbs throughout the years I believe.

Generally, yes you can. It will affect the performance, and likely not for the better without modifications.

Good luck.

Thank you saved me a costly mistake.

What year are these carbs an what kawasaki bike do they go on,Kei Hin v153 wk17?

The KZ-650/700/750/900/1000/1000J/1100 all have the same carb spacing. The GPz750 used the same carbs as the J model 1000 & 1100 albeit they had totally different jetting. Guys swap these carbs all the time. All it requires are different manifold boots and re-jetting. As long as you stay away from the Keihin carbs and stick with Mikuni you should not have any problems that can't be resolved with ease.