Expo leafs gave me about 1.5 inches lift in the back, which is about on par with what I have read elsewhere, if not a little low. The springs I pulled may be a little clapped out, but for 28 bucks I won't complain. I haven't driven on them much yet, but the ride is decent. I have 4" lift springs on the front of my truck that are too stiff for my taste. I have been looking at stock replacement F150 coils that are rated at 366 ppi, which is not too far from what came in the Ranger stock. I have read a range of things about F150 springs in Rangers including that they give anywhere from 2 to 4 inches of lift and can be too stiff, depending partly on the weight of the Ranger I'm sure. One thing for certain is that they are cheap. I have an extra set of Moog cc824 springs setting around that I am going to try. Going by Moog's specs I believe they should give me 2.75 inches lift from stock, though I am hoping for a bit more. I will hopefully get them in within a couple days.
Your lift in front will be limited by how much you can adjust your alignment. I'm not sure how much lift you can get without bent beams or drop brackets and still get it aligned. Someone else here may know, or you could probably turn it up in a search. There are aftermarket caster/ camber sleeves available that will give you more range of adjustment, but I don't know how much. How's the diesel run? I have never seen a diesel Ranger in person.