[dontlifttoshift]

Your existing housing can be used, no problem there.

Axles can be cut for 35 spline exterior and 31 spline interior if you were looking at a GMR setup.

Does your SVO brake setup have the internal expanding shoe or is the e brake on the caliper? The explorer caliper takes up a lot of space and isn't really necessary, you don't need the floating caliper.

What is the distance from the wheel mount surface to the framerail / inner wheel house, whichever comes first.

How far from WMS to control arms and or your coilovers?

How important is a parking brake?

Didn't realize you were still running ball bearings, the A20 is a better choice but not the end all. With floating calipers already in place I would be willing to try the A20 bearings, it would be a much easier choice if you didn't need axles. I went through several sets of A20 bearings on my roadster, but the loads it was seeing verge on ridiculous. 31" tall tire on a 20x10 with 3 1/2" backspace.

When the bearing retainer is tightened on the A20 bearing the rubber seal between the two halves expands to seal on the ID of the housing end and is then fixed in place due to the clamp load of the bearing retainer. The axle spins inside the seal. The seal works well as long as there is no end play in the bearing I never actually hurt the bearings, but the retainer would bend, then we had endplay and the seals would leak.