Hello guys! I just bought used ct engineering coilover sleeve (adjustable springs) from Craigslist, the seller however didn't tell me which one are the front. How could I tell? I checked the springs and I forgot the actual code but I remember they were all the same but two had "F" (i.e. FGC) and the other two didn't have it (i.e. GC) Installing in an hour so would love some help! Thanks!