I hope there's no harm in opening up an old thread like this one.
I still have lots to learn about these Explorers and cars in general, and so I'm curious: what makes the coilovers better than the stock torsion bars?
Also, of the people that have done this, what have your long term results been with the swap? Better alignment? Improved handling? Easier maintenance?
Depends on perspective and use.
What are you going to use the vehicle for? Slow speed off road, fast speed off road, drag racing, track racing, plain old daily driver? For a daily driver on the road, these are not needed. A good quality shock, combined with a good tire, and quality suspension componants, will be sufficient.
They do not affect alignment at all, good or bad. It's when you go to a much larger tire, that effects the camber, from the upper control arm length. That's a different thing altogether.
With a good set of shocks, there is no maintenance to speak of, other than adjustments on how they perform. Spring rates, valving, etc... Safe to say that if your going to the expense and effort for this conversion, you will be upgrading or replacing anything worn out anyways.
Now, the handling is greatly improved. This is where they shine over stock torsion bars.
The coil springs replace the torsion bars, and the quality of shock choice is greater. Both can be had in different configurations.
These float over bumps or holes, compared to a torsion spring in constant twist. Cornering is improved. Steering is improved. Therefore the quality of performance is improved.
Rebound & extension rates are increased, and tunable. Your options for a better ride is increased massively, with all the combinations available. You can fine tune this setup to your specific vehicle's needs/use.