The SN95 8.8 would be a bit wider than the original axle... The original '65-66 housing is 52-1/4" flange-to-flange. Here's all the 8.8 info you should need....
The 8.8 axle was released in '83 and made its way into the fox platform in '86.
Factory Mustang and other fox body cars.
Housing width is 59.25" with zero center section offset. Axle shaft length is 29.25"
Brakes are 9" or 10" 4 lug Drums
Gear ratios from factory are normally
2.26 for 4.2L v8 auto 78-82
2.47 for 5.0l v8 auto 79-??
3.08 for v8 all trans 82-84/5ish?
2.73 for v8 manual 87-93
3.27 for v8 auto 87-93
3.27 in 7.5" for N/A 4 cylinder
3.45 in 7.5" for turbo 4 cylinder (except 85 and 86 SVO and below 87-88 TC)
Popular Swaps
All numbers below are based on comparison to factory fox body mustang.
87-88 Turbo Coupe and 93 Cobra 8.8" axles are basically the same with 30" (3/4" longer) axle shafts meaning, they are 1.5" wider overall.
brakes are 10" 4 lug vented rotors
Gear ratios from the factory:
3.55 for the manuals
3.73 for the autos
3.08 on the 93 Cobra
87-92 Lincoln Mark VII 8.8 axles are 30.5" (1.25" longer) per side, meaning total width is 2.5" wider.
brakes are 10.5" 5 lug vented rotors
gearing is normally 3.27 or 3.08
SVO and 87-93 Saleen shared these axle shafts.
94-98 SN95 8.8 and 7.5 share the same 30" (3/4" longer) axle shafts, meaning they are 1.5" wider overall.
have two options for rear brakes
GT and v6
10.5" 5 lug non-vetned rotors
cobra (non IRS only?)
11.65" 5 lug vented rotors
99-04 SN95 housings are 3/4" longer per side, and the axles are 1.5" longer per side but they continue to share the 94-98 rear brakes.