I've flipped alot of ranger axles and seen varying drop amounts. Keep in mind if the truck is a 7.5" or 8.8" axle as the axle tube is a different diameter and so an 8.8" drops it a hair lower because its bigger around, and if you have an explorer 'big bearing' 31-spline 8.8" swap you get another little bit of drop as the axle tube is even bigger in diameter than the ranger 28-spline 8.8".
As well as over the years and models as well as extended cab vs regular cab there have been variances in the leafpacks, and a thicker leafpack will equal even more drop once you put the axle on top of it. Super cab v6's have thicker packs than 4cyl regular cabs so supercabs usually have more drop with a flip.
I have done rangers that have gotten everywhere in between 4" up to 5.5" of rear drop with just a flip depending on it's combination of cab-type/model/year/leafpack/axletype