explorer 8.8 in an a-body: experience needed

8 3/4 vs. anything else yet again.

8 3/4 is the best diff available from Mopar for your car. Taking it out may seem to be a downgrade and possibly a loss of value for your car. If you do trade it out, keep the 8 3/4 for the next owner.

However......

The 8.8 Ford is plenty strong. The Explorer diff has disc brakes. It is also cheaper to work with as it is still current production.

The 8 3/4 has been out of production for over 30 years, (as has the 9" Ford). Parts are getting pricey.

That $200 junkyard diff will cost more cash to install. It looks like you already know what you will need. You will have to change spring mounts,figure out your emergency brake cables, modify the driveshaft and add the Ford style flange. Do you have to renew the brake pads and rotors? You will need to change the master cylinder. Possibly that $900 rebuild does not look so bad when you factor in all the costs?

On the other hand, once you have it in place, repairs will be cheaper and easier.

It's your car and if you want a different differential, that should be your choice. The 8 3/4 is not the best differential of all time, (despite the tunnel vision some folks experience.)

I don't know how much strength you need, but I would consider the 8 1/4. FMJ body diffs are about 3" wider than an A body, just stay away from the 2:45 ratio case. Impossible to change to a better ratio. Cherokee/Wagoneer disc brakes are a bolt on.