When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
It is my undestanding that the '04 and maybe late '03 had their suspensions modified to reflect track results at Germany's Neurmburg course. I know for fact this was a major GM sales pitch for the 04 ZO6 CE, in fact mine has the tags to ID suspension tuned. So there must have been a difference. I know the 3 volumne tech manual I viewed once had the GM Part# for every component in the car. Maybe the Gm parts dept. can help. Try clicking the add under parts catagory.
Over the years the shocks, and a few components have been upgraded or changed. Can't recall all the specifics but I believe this site outlines most of the changes year to year.