I already pointed you to the right info. Again, oem Mustang LSD or the Yukon LSD. Not sure why you’re saying nothing is available. There’s even a full spool but that’s not what you want.

 

Your best cost effective option is the Yukon LSD.
UNBROKEN already pointed that out for you.
https://www.f150forum.com/f118/super...ential-457530/
Another thread about it.https://www.f150forum.com/f123/super...457580/index3/
The OEM LSD in the previous generation trucks had a fair bit of problem with plates failing.
Partly due to the vent tube.
However a long time Ford tech told me all the plate issues started when Ford switched to synthetic oil in the differential.
His advice was use 80w90 with the friction modifier and everything will be fine.

 

So I read through those two differential threads.
What I don't understand is why dealer parts man can't find a OEM LSD in the parts book from a fleet truck?
Because LSD is still offered for fleet truck orders so what is the problem?