You are doing exactly what I am. H&R OE Sport springs are in my future, and these bushings will get it back to ~ stock ride height and improve body roll and squatting during acceleration further, even beyond what the H&R springs do.It does, but if you measure it correctly it would be barely noticeable. I had them in my GTO and in my Camaro. Going to order them once I swap the suspension to the H&R OE Sport. They increase the spring rate slightly, preventing the hard squat you get when accelerating.
They used to have only 2 compounds when I bought mine a while ago, orange and black, now they have 4.