You need a big piston up front to work with the Explorer caliper out back. Are you using the factory calipers up front? If you have room for a 11.75 rotor (15 inch wheel) you might want to upgrade the front rotors. All you should need would be the bigger rotors and the taller caliper brackets. You shouldn't even need to bleed the brakes, just lift the calipers off and change the rotors and brackets and drop them back on.
I figured I would need to change the master and distribution block. The car has 18" wheels that I bought in that size specifically for upgrading the factory front disc to a 13" rotor. I do have the 11.75" brackets though. I may just do that and see how it works for now since the budget is shot already. Trouble is I don't want to change the master twice if I decide to go 13" brakes up front later. Eh, I'll figure it out in the Spring.
