Not a full answer and no pictures, because I didn't lower mine much, but if you were to lower it severely and want it to still sort of work:
1) Adjustable rear upper control arms are necessary to correct the pinion angle
2) Adjustable front upper arms (SPC sells them) are necessary because you can't get enough shims in the stock setup or the popular aftermarkets arms (Rideteck/UMI/Speedtech) to fix the alignment if you really slam it
3) If you want it not to bottom out all the time, the spring rates are going to need to be REALLY high. Like 800-1000 lb/in in the front, and 350+ in the back.
Take care with shock selection, too. You need a shock with a stroke that works in the range of motion you're going to end up with and the spring rates you'll need. I never got past the first three points before ruling out lowering mine, so I have no idea where to look for the right shocks. But I do know Bilstein's motorsports division will revalve a set of their shocks for something like $200 each, so it's doable.
Ridetech single adjustable coilovers front/rear. Ridetech upper/lower control arms front/rear. The car is lowered 2" all around. The wheels are:
Budnik Tillers 5
Front: 17 x 8 with 4"bs 245/45-17
Rear: 17 x 9.5 with 4.75"bs MICKEY THOMPSON ET STREET RADIAL II - 295/45-17 (Rear fenders rolled)
There is some rubbing on the front passenger wheel when going over dips in the road.
I am thinking of going with 18x8 fronts and 18x9 rears when the gbodyparts GNX replica rims come out.
Customer Donnie Brooks ride with the New RideTech "Street Grip" complete suspension from us. Comes with single adjustable shocks with lifetime warranty too. 2" drop and the ride is Fantastic!
Here is a link to it ---> http://www.gnsperformance.com/rt-coil-packages Only $2,500.00 for the whole front & rear system!
We have been selling and installing suspensions on G-Bodies for many years now... We have installed and tested every suspension we sell so we know our products inside and out, we are
Not just a place that sells anything just to make a quick buck! We know what works, We know what fits, and we know how well they hold up and perform!
This car's never been to the track but on street launches, it goes hooks pretty good and straight. The handling and driving experience are much better now. And I should've said I also bought this package from Scot at GNS Performance.