Completely different chasiss on your car than those springs are designed for. You need a firm grasp of suspension design before you just swap parts from random cars. 00+ guys were looking at STS stuff for their setup IIRC< but you grabbed CTS stuff for a 92-99? They weren't even designed on the same continent...
Hell that'* a Lighter. RWD car with an aluminum engine, spring rates, an f/r balance will be NOTHING like your 3500lb FWD Iron V6 car...
GM techs don't do anything like this either. I'd try to return them before you use them and can't.
'06 Vee Dub GTI 2 door Tornado Red
- 2.0 Turbocharged, Intercooled, Direct Injected, 6 Speed DSG, Underbody Aero, 17" Classix
- Moonroof, Bi-Xenon headlamps, Interlagos Plaid Sport Seats, 6 Disc In-dash, iPod integration, GTI Monster Mats (winter)
'93 Bonneville SE Purple Pearl H4U package - picked up June 23, 2003, Traded-in June 28, 2007...