the 7.5 would be ok if your doin a 5.0 swap and dont want posi. if your goin any bigger than a 5.0 i would get a 8.8 rear. the swap itself isnt that hard. you just have to fight old rusty stuff, but is nothing a s*** load of penetrating oil cant fix. i just did the swap in my 93 coupe bout 5 months ago and i think the hardest part was gettin the dam brake lines replaced and flared
yea i would go with that if you have the money to do that swap. we have had a couple of shelbys come in here at work with rear end noise complaints and the housing itself was actually stretched wider from the power
It depends on how the torque is getting to the axles.. if you run a 5 speed and lauch pretty high it won't last long. However if you run an automatic there is no real big bang of power hitting the axles, I've seen a 82 mustang run 11.6 in the 1/4 mile, C4 automatic, and 7.5" rear.
A stock 5.0, or even 3.8 in a few cases can break the 7.5. When not abused the 7.5 can last a very long time. The AOD cars are much easier on the rearend than the stick cars are.
BTW, early Fox v8 mustangs with the 7.5 will also have traction lok.
7.5 will hold up a little while. They are not posi, but when I did my 5.0 T5 swap into my 4cyl coupe, I rolled on the 7.5 axle til my 8.8 was built. I one wheel peeled it around town for a few weeks, and no breakage. My 5.0L engine was stock, with exhaust.
You can make the 7.5 a posi, and weld the tubes if you don't have access to an 8.8. The swap is easy as said, I would also buy some LCA's while it's out. That will help wheel hop, and traction.