They are revalved Bilsteins with Sleeves and the work was done by FCM. Other than that I don't have much info on them other than the spring rates and that they were used for only 10k Miles before being removed during a partout.Sounds like a nice selection of parts. I am a little confused on the coilovers...are they Fat Cat Motorsports coilovers(built, spec'd by Shaikh) or they revalved Bilsteins with sleeves, etc.?
Some say there is no difference but I'm not here to argue that point, just clarification. Either way should make the miata ride/handle much better.
P.S.-If they are Fat Cat Motorsports coilovers then depending on what series, etc. will determine how much you can change the spring rates and still be suitable to the valving, etc. The 2040 coilovers I had several years ago, iirc, Shaikh only recommended a 50-75lb spring change, up or down.
These didn't cost me much as I was able to get a really good deal and my stock suspension is abysmal at this point(like go over a divet in the street and damn near crack all your teeth from how upset the car becomes) so I know these will be a good improvement if not a MAJOR improvement.
Depending on how dialed in they are and how the car drives with them will determine how long they stay on. I plan on going Xida at some point in the future regardless so these will more than get me by until then.