Here is a little info I figured out when I was going to use the Explorer brakes on my project that may help.

Ford Expedition calipers have the same bolt pattern as the Explorer's. They have a slightly larger bore. It's only about 1/8", but it will make a difference in clamping pressure and bring you closer in size to the GM metrics.

Also, the Expedition pads are so close in size to the Explorer's, that they could easily be made to fit. They have a larger friction surface. The pads will almost fit as is. The Explorer rotors have enough width to just accept the Expedition pads. This will increase the "swept area" of the brakes and increase friction as well as reducing pad wear.

I changed over to the SVT Mustang brakes on my project and never got around to making the swap, but have the parts in hand. I'll put them on my 46 when I finally get around to it. I feel like I could use a little more brake power on it because it's so heavy.

Just something to think about.