The mounts are the same from '79 to '95. What's different are the tail lights, license plate lights, gas doors, mud flaps and mounting brackets, and tailgates. Regarding the wiring, you may need to get the plugs and a short section of wiring from the donor truck. I can't remember if the tail lights from different years use the same plug or not, but that may be different and something to be aware of. Perhaps someone else can chime in about that.

You must swap a short bed for a short bed, or a long bed for a long bed though. A short bed will not fit on a long bed frame or vice-versa.

You will want to keep the tail lights, tail gate, fuel filler door, from the new bed. I even saw a Tacoma bed on an '84'-'88 style pickup yesterday. I didn't get to see it up close, but it may be possible that even Tacoma beds use the same mounting pattern.