I've been doing research into potential donors for my 83 Tbird and it looks as if a number of Aerostars from the late 80's and early 90's have 7.5 Diffs with 3.73 and 4.10 gears. Any mechanical reason like spline count or something why that wouldn't work in my car? I imagine a mini van would be driven alot more gently than a TC, Mustang, or Ranger so it would theoretically make a great donor vehicle. Thoughts?
Oh no... *hands 7.5 flame suit*
The axles can be used for 5-Lug conversion so I can safely assume that if the diff is indeed a 7.5 then you can use the ring & pinion. Same spline and all that. Assuming you are just taking out the diff and not the acutal housing. It is offset to one side for one and I'm pretty sure the mounting points are not the same.
Now that that's taken care of...
HOWEVER, many here will tell you to squash all that and just get a 8.8. I for one have never had a problem with my 7.5 in Darkthunder or the 85 Stang that it came out of (and returns too when the 8.8 is acting up, lol). Which ever rear you build is up to you.
Well I fully intend to build up the 7.5 despite most people's attitude on the subject :P I want to find a locking diff with 4.10 gears to transplant and the Aerostar looks like a prime candidate, largley because I won't have to sift through acres of pick-ups looking for one that actually has a 7.5 (tried that on the weekend with no luck). And when my engine has powered up a bit more I can start thinking about aftermarket axles and so on. One thing though, my shop manual is extraordinarily vague on the whole subject of differentials. If anyone knows of a good resource on the procedure I'd love to know about it. Specifically one thing I'd like to know, do the axles have to be removed to free the differential?
The diff would be the same.