Crower rates the 66380X2 spring at 1.800" installed height with 173 lbs.
Page 172 here:
http://www.crower.com/media/pdf/2008b/166-180.pdf
Paul K tested a set and found about 210 at 1.800"
Which brings up the subject to never trust catalog published specifications.
Always test your new springs at your actual verified installed height.
.
__________________
'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 )
Old information here:
http://www.hotrod.com/articles/0712p...tiac-trans-am/
Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine)
5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension
https://www.youtube.com/watch?v=qDoJnIP3HgE