I just recently swapped the 8.8 rearend, rear disk brakes, front spindles, and front disk brakes from an '03 Mach 1 to my '89 LX Fox. The rearend bolted right up. The disk brakes gave me problems, though. I had to get the fittings off the Mach 1 and plumb them onto my brakelines. Also, for some reason the steering rack assembly and steering arms coming off the spindles are wider on the SN95 style body than the Fox body. The toe angle was ridiculous when I first got the car back together. a quick trip to the alignment shop (tires squealing the whole way. good thing it was just around the corner) fixed the problem. It looked like a pidgeon-toed 4th grader.
Anyway, as a note to all who attempt this swap, I suggest also getting the steering rack and the master cylinder off of the Mach 1. I am probably going to buy a Cobra brake booster off of the 93 Cobra since it had disk brakes all the way around. Should work perfect. Anyway, I just thought I would post that just in case anyone else is thinking about doing that and I could save them some trouble. It is definetly worth it, though!
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Stephen and the Blue Demon
89 LX vert
Holley 750, Edelbrock Vic Jr, TFS T/W heads, FRPP X cam, Crane 1.6 rr's, longtubes w/Dynomax Bullets, PA Super Comp C4 w/brake, Precision Performance Kwik Shift II, Art Carr 3200 w/ ballooning plate, NOS super powershot plate, complete UPR tubular front suspension w/coilover conversions on Lakewood 90/10's
Mach 1 parts swap 
