I had them on my old GT. The directions didn't say when I installed them, but make sure you cut that bushing on the strut. If not, you'll bottom out way too soon. Just in case you didn't know. I didn't. I took them off when I traded in my GT for my GTS. Gonna put em on the GTS soon.
I only had to cut them on the front shocks, not the rear. It's a "0.6 Inch" Cut.