Yes, I did that conversion on my 87. I followed the instructions from the net, and I did it with the axle still on the truck.
Just be warned that the instructions are a bit soft. "Just grind this" and "just tap this out" were 45 min of grinding and 30 min of a punch and a 10lb hammer. The place you need to punch out of the back of the diff is right on the factory fold, and its a B**ch to get it started. I also didn't weld around the one hole. I had no problems tapping it on the shoulder.
Also, if you don't get the switch with the locker (like me) you have to wire up your own. All the instructions I found said to use a DPDT relay, which is nowehere to be found. I looked alot of places, and a couple could order me in some for like $35 each, so I justed rewired it to work with four regular automotive 12V relays, and two pushbuttons. Red to lock, black to unlock, with an LED that is lit while its locked.
If you have any questions, don't be afraid to post.
87 runner, 4500 lbs dry, auto tranny, 22RE, very slow on hills, flats and downhills....