Hi mate, "cushion lever" is also known as "bell crank" and is the rocker arm between the shock top mount and the struts that attach to the swing arm, it pivots on needle roller bearings with a bolt through the centre. Dproject is "the man" on these, I know the rocker/bell crank are different, the shock and struts and swingarm also different, I have owned/raced both models (a LOOONG time ago!) and didn't know the frame was different other than colour, maybe Dproject can throw some more light on it?
Jason?
?? Both bikes in good nick are superb, the D is a little slower than the Z but was much easier to ride faster for longer back then
Kt.