I have researched all the RPO codes to my '89 and I don't show the Z51 or the FX3 package according to the codes. My interest is this, I wrecked the car about 9 yrs ago and the shop took quite a long time to repair due to delays. The shop manager told me that it was more difficult getting some of the Z51 parts? Now either he was using this as a line just for being late or could my car have these items? Is there a way to easily determine if the car has the Z51 package? Something short of a micrometer on a swaybar or something. Just want to solve the mystery so I know where I'm starting from, with any potential mods. This is the only C4 I've owned so I don't know if the susspension is Z51 or standard.