Part Number:JD49D2. Mazda Miata 1990-1997. Front Lowering:1.5 in. Rear Lowering:1.5 in. H&R Special Springs Race Spring Kit. H&R Springs Race Spring Kit. Race Spring -- 40. (hf) 54SiCr6 Spring Steel, Shot Peened, Block Set, Lightweight, Strong and Resilient.