I'm looking to purchase one as well. What year(s) are the most desirable? I've heard that some come with a heavy duty transmission and some with larger brakes; if so, how do you tell. Additionally I've heard that the superchargers are slightly different between years and some respond to modifications better than others. Just looking for some general info before I purchase, as there's a lot out there relatively cheap.
well assuming you are also looking for a regal gs in specific like the original poster the changes from year to year are not that significant mostly minor stuff
97/98 had a very restrictive airbox and a throttle body with a post down the middle 99-2004 had an improved airbox & tb but most people modding them would ditch the airbox pretty quickly for a fenderwell or cold air intake
97 & 98 had a slightly different blower with different vacuum routing
grand prix gtp's got a much improved gen 5 blower starting in 2005 that is a popular retrofit to regal gs's , impala ss , ultra's ,riv's ,etc... as is porting the gen 3 that came on these other cars
99-01 got front strut tower bars while the other years didnt unless it was a "GSX"
a performance shift switch was included up until 2001
2003 & 2004 trannys got an upgraded 4th gear hub
they all had the same brakes but brake & suspension upgrades from police package impalas are popular as well as f-body and corvette braking conversions
there are too many subtle changes to list or remember , but there is a thread about it with a lot of little stuff people have noticed over on
redirect ( I am a moderator over there )
everybody has their own opinion on which year is the best over there but myself owning a 97.5 , 2 98's , and a 2002 my advice is buy the nicest newest one you can afford-they got better as they built them but 99-02 seem to be the ones with the happiest owners
my 2002 is my daily driver it currently has 169,000 miles on it and still runs & performs awesome on the original untouched long block & tranny ,has never needed anything but fluids , filters, & tires and I commute over 1,000 miles a week with it , get around 30 highway , and stop in the track on my way home and run 13.5 @ 104 1/4 and 8.6 @83 1/8 on minor bolt ons
they are all good cars if maintained properly you may find a mint 98 for the same price as a not so mint 03 just consider age price and condition