According to wikipedia
http://en.wikipedia.org/wiki/Z32#Z32 the z32's aluminum calipers were changed out to the iron calipers in 1992.5 to help warpage/shimmy problems.
But talking to people, some say aluminum better = lighter, and something or nother... i forget... bigger? ... or something. can anyone with the aluminum/iron swaps vouch for this?
sorry mods if this belongs in tech...please move as needed thank you