Ok to sum up my findings.
STOCK rate
Front Linear 143 lb/in
Rear Linear 120 lb/in
Eibach
Prokit p/n 3865.140
Rates
Front PROGRESSIVE rate 154/200 lbs/in
Rear PROGRESSIVE rate 108/165 lbs/in
Supplied #'s from Eibach
1.3" drop front and rear
http://www.wbodystore.com/grandprix/suspension-c-6.html
B+G
p/n 68.1.003
Rates
Front Linear rate 178.75 lbs/in (25%)
Rear Linear rate 150 lbs/in (25%)
Caculated #'s from percentages from B+G
1.2" drop front and rear
http://www.wbodystore.com/grandprix/suspension-c-6.html
VOGTLAND
P/N 959206
Rates
Front LINEAR 200 lb/in
Rear LINEAR 140 lb/in
Supplied #'s by Vogtland
1.4 drop front and rear
Sport Lowering Suspension Springs Vogtlandsuspension.com
or these are about 20 more but are definitely in stock
Swift Motorsports
SSC
No part number listed on there website
Rates
10-20% increase
Front Linear 157-171 lb/in
Rear Linear 132-144 lb/in
Caculated #'s from percentages from SSC
1.8" drop front and 1.6" drop rear
Sprint Springs
Part # 3050
Rates
20% increase
Front Linear 171.6 lb/in
Rear Linear 144 lb/in
Caculated #'s from percentages Sprint
1.8" front / 1.6" rear
CM springs (Canuck Motorsports also on eBay)
Front Linear 190 lb/in
Rear Linear 140 lb/in
Supplied numbers from CM
1.6" front & 1.4" rear drop
eBay Motors: CM Lowering Spring GRAND PRIX 97-03 02 01 00 99 98 drop (item 170211250005 end time May-16-08 16:53:55 PDT)
WBS Springs
Front Progressing to 400 lb/in
Rear Progressive to 350lb/in
Number supplied from WBS
1.6" front & rear drop
http://www.wbodystore.com/grandprix/suspension-c-6.html
Found this on clubgp so if spring rates are wrong Im sorry. Let me know if they are and I'll change them
