First of all......Good luck getting 3". If you are installing a V8, you may want to wait and see how the car sits once the 8 is in.
As far as S10 spindles lowering our cars, I'm not sure where this came from. The S10's and the GBodies used the same spindles. Until recently, I had never heard that they will lower the car. However, I cant verify how the newer 98-02 spindles compare to our cars as far as ride height goes. These will bolt in and give us the 11" dual pistons brakes.
If you plan to lower the car 3", you may want to look into Air-Ride. I've never seen a static dropped GBody to 3" without some major modification. You'll need to do some cutting, molding, and re-welding to your innerfenders and wheel wells. Now, if you want 2.25-2.5, thats do-able. You'll have a few options for the front:
1. Poor ride quality but it works: BellTech 2" spindles and lowering springs (I like Moog 5658's)
2. Great ride quality: Howe's tall BJ's, SPC upper arms, Lowering Springs
3. Poor Ride quality: Cut stock springs, BellTech spindles
For the rear, unless you want to get into coil overs, you'll be limited to lowering springs and the most you'll get is with a set of Eibach rears, about 1 3/4". I prefer the BellTech rear springs because they are consistant and dont sag after a couple years, they'll give you 1.5".
If you want to go lower, you can cut F-Body non progressive springs but you'll end up with poor ride quality. Otherwise the best way to lower the rear is with a coilover set up.
