IMO it would be easier and more straightforward to just get a 95+ Explorer axle to start with than to convert one that came with drums.
For your '86 you will either need a driveshaft out of a newer (90+) truck with your same bed/cab configuration if you have an automatic, depending on transmission lengths you may be out of luck with a stick other than the M5OD.
Another option (the route I took) is the drill and tap the smaller boltpattern onto the flange. I had it off to replace the seal anyway and just ran it down to the machine shop and had them do it. Removing the flange requires resetting the preload on the pinion bearing, if you don't know how to do that you will need to find somebody that does.
A custom driveshaft is always an option too.
This way you get a much stronger more popular axle that is easier to find goodies for down the road, and the disk brakes that you want. FWI, when you grab the axle, it is a great time to grab the springs too to eliminate the typical Ranger lean.