don't waste your money, mustang up the rear! You'll get vented rear rotors, and a huge selection of pads and rotor upgrades to choice from than an explorer rear brakes.
Get the caliper brackets, anti-moan, calipers, and rotors.
Modify the caliper brackets like they do in this link:
Or, you can buy the brackets with four holes if you don't like three holes. The modified brackets are about $150 depending on where you go.
Junkyard it up for under $100 for rear brakes and know what kind of condition your rear end is in. Or buy that $300 unknown condition axle and gamble.....seems like an easy choice to me.
If you go with the custom made brackets for ~$150, you can get the cobra rears brakes, which have a diameter of 11.65". They would match your front!!! lol