i used an explorer 8.8 in my 68 valiant. i bought a second 'short side' half shaft from summit
SVL Drivetrain Products 2022636-1 SVL Drivetrain Axle Shafts | Summit Racing which as you say makes it pretty much A body 8.75 width. as well as lsd and disc brakes, they also have bigger 31 spline half shafts so nice and butch. plus with so many fox mustangs being raced parts are readily available and more importantly cheap compared to the 8.75 axle. like pricing a small or big block chevy rebuild compared to a small or big block mopar, you get the idea.
my valiant had 8 1/2" slot mags with 295 50 15's under the stock arches using the 8.8 with the 2 short shafts. i rolled the arch lips but that was it.
neil.
I found a bare axle length for a 94-98 Mustang GT/Cobra of 29.937". With that and the cross pin size of .875", I get an overall width of 60.75" (flange to flange).
Based on the published 68-70 B-Body axle length of 29.1875" and a thrust block length of 1.5" the overall width from flange to flange is 59.875", .875" narrower than a 94-98 Mustang 8.8. This jives with the published 60.125" (drum to drum) width if the thickness of the drum is .125".
To match the B-Body axle, the target length would be 29.5" for an 8.8 bare axle.
The Explorer overall width using the same method as the Mustang is 59.375. This is 1/2" narrower than the B-Body axle and still has the pinion offset. The long side axle is 30.6875" long so potentially one could shorten the long side 1.1875" and add 1.6875" to the short side and then buy some custom axles at 29.5" long. This would result in an overall width that should match the B-body housing.
The question is, how much would it cost to shorten one side and lengthen the other? I would assume it would require 2 housings (one to cut the longer tube off of). The custom axles appear to be $500, but I didn't look any further than Moser.
Another (better?) option would be a 99-04 Mustang housing. The axles for that application are 30.75" long and it is a symmetrical housing, so in theory one could shorten both sides 1.25" and only have to buy one housing. No idea how much a 99-04 8.8 costs though.
If you are paying to have a housing narrowed and buying aftermarket axles anyways, probably a wash. But if you could buy a clean 68-70 B-Body 8.75" for $500-700(?), and use the stock axles and not narrow the housing maybe not? Don't know.
Oh, and the 79-93 8.8 bare axle length is 29". So overall width is an 1" narrower than the B-Body width.