In the photo to the right I've pointed out the two tiny tangs that locate those outboard pads. During assembly be sure to capture the pads within the tangs, then secure with the slider pins. A small but important detail.
Next, insert the inboard pad, press downward slightly to pass the slider pins through the pad's locating holes, and repeat for the outer pad.
(I'm showing the '86-87 here)
Mistakes are not acceptable when it comes to our brake systems, so I proceed carefully, double-checking my work as I progress.