KONI "adjustable" shocks...it's what the Jack Roush Performance Engineering (JRPE) Stage II kit included with some GTC cars. There were 4 total. Two up front and two out back. They took the "stock" shock's place which was the traditional setup for Mark VII cars and swapped them out with a much better, fully adjustable performance shock. They worked in conjunction with the Goodyear designed stiffer front air springs and bigger diameter swaybars that came with the Stage II kit from JRPE. They were a vast improvement over the stock setup on the LSC cars. Each car also received a shock key which was used to adjust the dampening for each. If you dialed them all the way up, the heavy Mark VII handled like a go-cart. Truly impressive. Those who enjoyed the smooth air ride of the standard Mark VII received a teeth-loosening experience on rough roads no doubt. I, for one, am a big fan of them and love the improved handling on mine.
Interestingly enough, there is one known GTC that actually had the "quad-shock" system in the rear. This was four (4) KONI shocks that were installed instead of just two in the rear. The additonal shocks were mounted horizontally and connected from the rear axle to welded mounts on the frame. They are on a 1985 GTC Stage III, 5 speed car. You can view it in picture # 4 above.