these are based on 89-97 grand prixs but the mods are pretty much universal.
rear bucket seat conversion
http://www.clubgp.com/cgi-asp/mods.asp?modid=39
air box mod (home made cold with stock aperance)
http://www.clubgp.com/cgi-asp/mods.asp?modid=51
exhaust cutout (by passes muffler or cat and muffler at the flip of a swich for wide open exhuast)
http://www.clubgp.com/cgi-asp/mods.asp?modid=6
Rocker replacement (top end power gain)
http://www.clubgp.com/cgi-asp/mods.asp?modid=34
if you know of any links with mods post em
I'll post more later