All Rangers have the same length leaf springs as all BIIs. Explorers (up until they went to independent rear suspension) have the same spring length as well, but some Explorers got mono-leaf rear suspensions. 4-door explorers will add lift to your ranger or BII but you should flip the centering pin over (explorers are spring under axle, rangers and BIIs are spring over axle).
Of course, if you want to custom build a leaf pack, anything with the same spring width is fair game to be cut down to your needs. I've been there and done that.
I usually go to a spring shop and get the replacement nylon/teflon anti-squeak pads for the ends of the leafs, a new centering pin, and a new set of U-bolts when I replace a spring pack. Might as well do it right while it's out is my thought. I usually smear the replacement pads with wheel bearing grease on both sides too, seems to prolong their life.
