Anime, you said: "though you can use a block and longer u-bolts for a cheap (and hopefully temporary)"
What did you mean by that?
Lowering the Explorer with Drop Blocks is THE best way to lower the rear, a modest amount. There are many reasons for this, but the 2 best reasons are: You don't lose any load capabilities with a drop block AND the shock length can remain the exact same...
So why should this only be a temporary solution?
Ryan
Blocks are a cheap, down and dirty, quick way to raise or lower a vehicle, but they are not the best way.
The use of blocks is the leading cause of axle wind-up and poor vehicle handling.
A vehicle is most stable when the spring seat at the axle is closest to a line drawn between the front and rear eye of the spring.
As the distance between the spring seat and this line increases, so does axle wind-up.
The more the axle rotates because of axle wind up, the less stable the vehicle will be.
For these reasons we do not recommend the use of blocks to change the ride height of any vehicle.
http://www.eatonsprings.com/blocks.htm
2 inch blocks are fine, though from an "ideal" perspective, I'd still say it's better to lower by getting de-arched leaf springs. On Explorers, especially 4-doors, this is as easy as getting 2 drivers-side leaf packs from a Sport (not the monoleafs though). They are worn out enough they will drop an inch or more, and the lower spring rate will lower a 4 door even more, with a softer ride. The load carrying capacity is reduced, but most lowered rides that tow use airbags anyway.
Much more than 2-3 inches is putting too much distance between the axle and spring...I have seen people stacking blocks to get 4-8 inches of drop. Dangerous to say the least. A single 2-3 inch block is okay, but really, in terms of a daily-driven vehicle, blocks are better left as a temporary measure to either see how the vehicle looks lowered, or get an idea of how much drop you need to get the look you want. But I do agree they are much, much easier for a "budget" drop that lets you use the stock shocks in the rear...but you'd need lowered shocks in the front going down past 2 inches anyway, so you might as well get lowered shocks all around if you go that far.
Overall it's probably fine for rides that are mostly show without a lot of horsepower or big torque that would wind the axle up big time. A torquey motor like the 4.0L or a V8 might lead to handling issues, especially with smaller than stock size tires. Blocks are usually best for mini trucks with 4-bangers, but for a mild 2-inch drop all around on an Explorer, sure, they'd be fine.
Mine lowered itself naturally. Now it's lifted with shackles and shims.
But if I were to lower it more than just old springs allow, I would do it with 2 inch Eibach drop coils in the front and de-arched leaf springs in the rear. I think the 4WDs look better stock height to slightly lifted though, rather than dropped, and it works better to allow more wheel travel.