Maybe, maybe not. There is an "S" stamped into diiffs that are LSD. But it's stamped on top of the diff, very hard to see. The best thing to do is jack up the rear and spin a tire. If the other tire spins in the same direction, you have LSD. If it spins in the other direction, you do not.
1995 325I, window tint, K&N, debaffled airbox, BMW #104 wheels, Nighthawk low beams, smoked side markers, smoked corners, smoked taillights, M3 stlye heated mirrors, various interior bits, Bosal cat-back.