ford explorer brakes on 8 1/4?

I saw someone saying that they can use explorer brakes with an 8 3/4 by drilling a 5th hole in the caliper bracket. If I'm not mistaken, isnt that the same mod needed for using grand cherokee disc brakes?? So would that mean that the explorer bracket would bolt right onto a 8 1/4?

I ask because i had no luck finding grand cherokee disc brakes at the junkyard. However, i found 3-4 explorers with disc brakes.