I shoulda posted earlier, but I spent a couple days putting in new parking brake shoes and rotors.... cursed a lot...
That said, I just returned from the Salvage yard with a rear axle assembly in the back of the Explorer. Nothing wrong with the one I have except it is marked "3L73" and the one resting on sawhorses in my backyard is marked "4L10".

Advertised cost was 250. Cost me 325 by the time I paid the "Core charge" of 50 bucks and of course Uncle Sam had to get his cut. The axle is off of a V6 so no Torque bar mounts. I'll have to find a set of brackets and weld them in. But it has about 80,000 fewer miles on it than the one thats in the truck now so it should be an upgrade in more than one way.
The front diff is on its way from a seller on Ebay. Low Mileage (80,000?) front 4.10 assembly for 100 bucks free shipping.
Anxious to get it all installed. Not so anxious to do the work. Probably have to do it in the backyard as the carport is pretty small. Good for short simple jobs, not so much for big week long jobs. Also occurred to me as I drove home happily that I had just busted my butt putting new brakes in the rear end that I am now going to be removing... grrrr... I get to do it all over again now. But at least the rear end will be OUT of the truck when I do all the necessary prep work.
If anyone in the Phoenix/Mesa area has some free time coming up in April let me know when... I'd love to have a helping hand with this job. I'm getting kinda old to be bench pressing rear axles... lol