Yes, they fit fine. If they're new or off a 4x4 Explorer in good condition they can provide up to 2" of lift over stock BII springs. Ranger leafs are also the same length but do not provide the lift of Explorer springs.
They're a common upgrade either worn or in great condition, stock BII leafs are a bit on the weak side.
I've used a bolt from the hardware store before for flipping the centering pin (never been successful removing the old one in one piece and you shouldn't really re-use 'em anyway), but then you either have to grind the head of the bolt or the hole in the spring perch on the axle. I've pretty much only done it in a pinch.
Usually I try to get to a spring shop and get new pads for the ends of the leafs and a custom pack "clamp" along with the centering pin, and since the leafs are more or less apart, I replace the wear pads and pack clamp before using a large C-clamp to put the pack back together and replace the centering pin.
Explorer front coils also fit without an issue. If you get ones off the same Explorer as the leafs, you can lift the front a lil too (of course, then you'll need an alignment).
Stock shocks should stretch far enough. I say should because I've never done that, my Ranger I built custom leaf packs and got more like 3" of lift and the 2wd shocks just didn't have the stretch, so I put 4x4 shocks on, lol. My choptop I did custom suspension and far exceeded the limits of stock shocks.
Brake lines will not be an issue.