Some ideas and questions about the FORD 8.8 axle:
My understanding is the Ranger 8.8 is a direct bolt in swap and has the pinion centered correctly. Why not just use that?
the Ranger rear axle is not a direct bolt in --spring pads have to be changed -- 1993 and up Ranger width is 58 inches overall -- Explorer width is 59 inches overall -- pinion offset is the same towards passenger side on both rear axles -- Ranger axles are 28 spline ( except for a few special 4x4's which are 31 spline ) very few have a traction -lok -- Explorers are 31 spline and majority have a traction -lok --
1-the stock A body housing is 58 5/8 inches wide axle flange to axle flange WMS (wheel mounting surface ) -
pinion offset -axle flange (WMS ) to center line of pinion--- passenger side - 28-3/16 inches --- driver side 30-7/16 inches
2- the stock Explorer housing is 59 inches wide axle flange to axle flange (WMS)
pinion offset - axle flange (WMS ) to centerline of pinion -- passenger side - 27-1/2 inches --- driver side 31-1/2 inches
3- the stock ranger housing ( 1993 and up ) is 58 inches wide axle flange to axle flange (WMS )
pinion offset - axle flange (WMS) to centerline of pinion -- passenger side -- 27 inches --- driver side 31 inches
4- the stock 1986- 93 Mustang housing is 59 inches wide axle flange to axle flange (WMS )
pinion offset - axle flange (WMS) to center line of pinion -- passenger side 28-7/8 inches --- driver side 30-1/16 inches
from the above the 1986 -93 Mustang rear axle is closer to fitting an A-body car as far as pinion offset and overall width is concerned -- but axles would have to be upgraded to 5 bolt in either 28 or 31 spline -- they come stock with 28 spline traction -loks but no real performance gear ratios .
if you are not concerned with the pinion offset ( although you should be ) use the Ranger or Explorer rear axles --- BUT driveshafts and u-joints tend to last longer when everything lines up correctly .