I'm running '94 LS calipers and rotors on my '91 L. They are slightly larger calipers and the rotors are thicker. They are a nice upgrade, really give the brakes a bit more muscle. Simply a bolt on ordeal with only a slight bending of the rotor backing plate to make the larger calipers fit (or swap the backing plates over too). Pads are supposedly the same though I have seen them listed as being different. If anything, the 94-95 pads are thinner to allow clearance for the thicker rotors (but I don't know for sure). They are the same shape and should be interchangeable IMHO. No clearance problems with my stock L wheels.
Charles