SLP Specification Bilsteins are the Best Modification done to the vehicle, replaced OE type shocks on the car (orange painted).
These are basically Bilstein HDs that have custom valving for the Gen4 F-Bodies that give a slight improvement over generic HDs.
These really steadied the car through turns, adding a bit of roll stiffness and actually reducing the jarring impacts and squirrely oscillations of the OE shocks; making the car much more enjoyable to drive both slow and spirited. Highly recommend for a budget damper setup if you don't really need Koni 4/4s.
Plug for Strano Parts: Sam will set you up with what you need for suspension and nothing less or more than you need. Best prices in the world, highly recommend.