I'm guessing 4-door Explorer?
Are the springs so loaded down the upper coil turns are right against each other?
You might be able to get a set of Skyjacker 6" coils to work on that truck, it sounds heavy enough that you might get around 4" lift out of them (which is within 1" of what your axle brackets are) and should be alignable.
The other option would be Skyjacker's 4" coils, although you'll probably want to run a spacer with these. However this option would be less risky for not being able to realign it, you'll then be able to adjust the final ride height using some washers.