Re: Drag springs for a VERY lightened rear
Reply #1 –
Rear springs are rated far less than 600 -950lbs/inch! Even with a torque arm the most you can get in the rear is 430lbs/inch. I have no clue what factory ratings are but SN-95 Stangs are rated at 210lbs/inch, which is the closest to the Tbird/Cougar. Aftermarket isn't kind to us so we have to use parts that are 'close enough'.
I would put the car completely on the ground before buying springs. Therefore getting the full amount of weight distributed to the rear. Even with jack stands on the front and rear suspension my car sits higher than it should. The flipped bracket works best with lowered suspensions. It may be in your best interest to buy a set of Cougar specific shocks if the suspension travel problem is not alleviated.
EDIT: I see your terms are just backwards. My bad.