Hello, I'm looking for some help. I have a set of springs that came with my 91 LX 5.0 hatch. They sit close to a 3" drop, the car corners like its on rails, but rides very harsh. They are red. Fronts sit 12" high free-standing. The only mark on them is "SP2100F" printed very small at the bottom of the spring. I've been looking and calling and googling for a week, and no one knows what these are. Search results get me parts for gas equipment in the UK, with ONE automotive link to American Muscles lowering spring page. But not to a specific company or spring. I called, they don't know what it is either. I've verified that they are NOT Eibach, BMR, H&R, SR. I will continue to call, but would appreciate any help. I would like to unload these springs in favor of some Eibach Pros, or even stockers. Thanks!