The brake rotor may be differnt. I don't know if the bolt pattern for it would be differnt as well. The sporockets are the same, I know that much. Looking at the parts websites, the two years have differnt part numbers. I'm guessing that has to do with the axle change and newer style brake caliper. However, 86-93 take the same wheel bearings. So that means the axle is the same diameter. The only "spacer" my 87 has, is the piece that the claiper bolts to...other than the bearing seals, if you can call them spacers.
I'm willing to bet that it will work for you. If your rotor does not bolt onto that hub, I'll be surprised. If the rotors aren't very far off in diameter, you could run the smaller one with your caliper. Wouldn't be the ideal setup, but it could work. Might need to dedicate a set of pads stickly for that wheel though if that happens.