Others have mentioned the 5662 and thats what I would recommend as well for a stock type ride height spring with a higher spring rate. Freestanding height they are shorter than g body springs but are much stiffer so they won't compress as much under load. It also makes them easier to install. While I didnt use actual 5662 springs in my Grand Prix I did use an original used set from an 89 GTA (5662 is what the replacement moog spring would be) that had about 80k on the clock. Much shorter than the sagged non f41 v6 springs that I took out but raised the car up probably close to 2 inches, though the orginals from the GP had over 160k on them and a sbc in it instead of the original v6. It was sagged so bad I don't think I could get a floor jack under the engine crossmember.
Well i took a vote with myself and now I am reconsidering your input and I've kept the 5608s in my cart. Now with a fresh set of eyes and a new cuppa joe let me rethink this........yes i want stock ride height and yes less compression............my OE springs may still be close to stock ride height but
their compression rate seems to be very soft maybe from age. I've installed new shocks, sway bar end links and bushings but mayeb the 5662s are what I really need. thanks for your input...................