Identify this part

Yes, but I have the original manual, Kawasaki KZ400 issued 1977, my bike is 78......

I found the clutch adjustment on the left side was wrong, and so now the pushrod fits and everything is fine except my clutch cable has a lot of slack. I am following the clutch cable adjustment, but it doesn't seem to be helping..

Any tips?

You need to identify your bike's exact model and then buy the Kawasaki Service Manual that covers that exact model. Otherwise you may run into problems because not all models are the same. Some folks get confused about what year bike they have because, for example, a KZ that was built in the latter part of 1978 will be a 1979 model. So the only way to know exactly what manual to use is to use the model number. Kawasaki made a couple different model 1978 KZ400 motorcycles. Those 1978 KZ400 models have differences between them, and some of those differences, such as disk brake vs drum brake, are pretty major, so getting the correct manual is important. If you are unsure about your bike's exact model you may want to take a look at the link below for additional info. Ed

www.kz400.com/ModelidentificationFrameset.html

and there were two very different clutch release mechanisms used that year. The adjustment procedure for each is different.

Thanks guys! Found out my bike is a KZ400 B1 and the clutch mechanism is different.
Also found my tension again, the assembly that attaches to the end of the cable and the pushrod was out of wack. I attached some pictures.
Put everything back together and now i can use my clutch again.

Did you grease it well?
Steve