So here is what I found as far as Exploder discs upgrades.
 
I was already running Crown Vic rear pads since they fit in the Exploder caliper, but are 3/8 wider and actually use the whole wear surface of the rotor.  Not to mention they are a hair thicker.
 
I looked into Crown Vic calipers a while back, I found that they are the same bore (1.88) on the Police package as the stock solid axle Exploder, but are phenolic pistons.  And since the Crown Vic and Grand Marquis have one rear rear mounted caliper and one front mounted caliper it makes the bleeder upside down if used on an Expo.  And the civilian Crown Vic only has a 1.182” bore w/ steel pistons.  The Civilian and Police models use the same size pad, but the clips are different to accommodate the thinner walls of the steel piston.
 
I looked into both IRS Exploder calipers and pads as well as 2001ish F150/Expedition calipers and pads.   I found that IRS Exploders use a phenolic piston caliper with the same bore and mounting as the older solid 8.8 Exploders, but use a wider/thicker pad like the Crown Vic
 
Here is where things get interesting.  I checked out an 01 F150/Expedition brake setup.  The 150 caliper uses the same style pad as the IRS Explorers, but its about 1/8” longer and will not fit in the Explorer bracket.  However the 150 caliper does bolt up to both the IRS and Solid 8.8 Exploder bracket.  The 150 Caliper uses a larger 2” diameter phenolic piston.
 
In order to use the F150 calipers I has to ditch my Crown Vic pads since the clips would not fit in the phenolic piston, but I picked up 2005 IRS Exploder pads which are the same width and thickness as my Crown Vic pads, but have a smaller clip with an offset that fits the phenolic piston.
 
On another note the F150, IRS Exploder, and Crown Vic all have the mounting tabs moved about 1/8” to accommodate the thicker pads.  The stock solid 8.8 Explorer calipers I was using barely squeezed over the rotor with the thicker Crown Vic pads before.
 
I also confirmed that the larger rotors from the F150/Expedition/Navigator will not fit in a 15” steel wheel and use the 5x135mm pattern.
I had pictures of the whole setup with all the different pads and calipers side by side, but someone stole my phone with all the pics.

