being as how the zx9 stem pressed in from the bottom and uses a snap ring to keep it from being pulled up and out,and the kz stem pressed in from the top and had a shoulder to keep it from being pushed through,and a weld on bottom to keep from being pulled up and out.i was able to press it together and weld the two.the step on the stem means it can't be pushed down,and the snap ring on the bushing keeps it from being pulled up.
it ain't goin nowhere! ;)