If out of a Mustang, the tail shaft will be an inch shorter (right size for an older mustang too)

Out of a Lincoln, or a truck, it’ll be longer and will need modification of the drive shaft in the car.

The later 91-92-93 I think AOD are even better as they have steel stamped drums , and some even have a bigger OD band .

Depending on what the person is doing with the car those two could be very important

TKOPerformance wrote:

If the plan is to keep it stock, but one used and just throw it in the year to year variations can make a difference. 

If the plan is to rebuild/modify it to improve performance its going to make less of a difference because you can just add the updated parts typically.  Hard parts like drums could potentially be harder to find, and more costly, so its best to get the newest one you can, but the band, clutches, etc. mean less when you rebuild it because even the stock style kits typically only come with the best version of the parts.

Definitely follow Gaba's thread on his AOD build if you're going to ope in up.  Really good thread, and he did a lot of research on the AOD, which is very important with anything you choose to rebuild/modify. 

Appreciate that!

And I have cast iron drums and sun gear shells for two AOD ‘s

Don’t buy any part before you contact me. (If you are in the US)

Definitely up to you, but Gaba went down the road I go down with this stuff.  You're buying a used transmission that's at best 25 years old.  You don't really know how many miles are on it most of the time.  You don't really know how it was serviced most of time.  You don't even know if it worked right when it was pulled.  I tend to just do things right, because I truly hate doing them twice.  There's nothing worse than getting a transmission installed and being all excited for the test drive, and something's wrong that ends up meaning its got to come right back out again.  This has led me to rebuild any used component before installing it. 

Racing or not, the transmissions were upgraded by Ford over the production run, as all automatics of any make are from my experience.  What this means is that Ford saw problems with them, even in the stock configuration, and made changes in an effort to reduce warranty claims.

I also view things like a good shift kit as mandatory for ANY automatic.  The stock calibration is just too much compromise.  A good shift kit (Transgo) will still have nice smooth part throttle shifts, but it will snap your head back when your foots on the floor.  This makes the car more fun to drive and also helps the trans last longer (less overlap during shifts means less clutch wear).