I have the FRPP N springs combined with the 2011 GT500 strut mounts and the FRPP dampners. I have been very satisfied with the comfortable, stable, firm ride and handling from this combo. The only thing it feels like it needs now are some poly sway bar bushings. Just have not done it yet. I have not rode in any of these cars with alternative spring / strut combos. For all I know there is another that is better. However, this one seems just right to me. Also the progressive nature of the struts is very nice. When grannying the car around and through turns it is nice and plush. Throw the car into a turn and it goes ultra firm immediately.
I did not do the plates. The drop was only 1.5". If you want it to be right then do not match up higher rate springs with stock dampeners. Spend the extra and get package that works together.
Here is the drop, these wheels and tires are about the same diameter as stock.
2013 Grabber Blue Premium Couple, Auto, FRPP N Springs, FRPP Dampeners, Lund Tune