Exactly.....
Selec-trac will decide how to torque fore and aft.....
for the rear diff:
True-Trac is a mechanical (helical) LSD that you would have to have installed locally aftermarket.
Track-Loc is friction plate LSD. Can wear out. But available from factory
Do you know anyone with a...
Apparently release has been pushed back until Nov, you will see that in one of the links on page 1,
part # is valid though
https://www.google.com/search?q=77072469AC&rlz=1C1AWFC_enUS889US889&oq=77072469AC&aqs=chrome..69i57.3383j0j7&sourceid=chrome&ie=UTF-8