You really do need to use the search function. A lot of your questions have been answered tons of times before and there is a LOT of good information to be found, just takes some time and some reading. Start with the how-to's.. the sticky's, etc.
To answer your question.. explorers... I wanna say 96 and up have disc brakes. They are 31 spline axles like yours... so it's not too hard to put them on your truck.