So after almost 15 years and almost 100K miles, I decided to swap out my static Billy/H&R combo for something adjustable. Went with Koni Sports and GC kit.
The old and new shock. I have AKG rear shock mounts the insert is still very good as it is only a few years old and not much mileage. I set the shot to a quarter turn before stiffest rebound to try it out.

New shock all together:

Old OE Sports vs GC adjuster and Eibach spring. This is lowest setting to demonstrate but I have set it to something between HR race and sports

Springs and adjuster installed:
