RV6 wrote:

The rabbit hole is so deep, where does it end?

My little 67 is a peg-leg. Originally she had a trac-loc installed but that ended when I swapped the pumpkin for the 3.55's in there now.

I don't do burnouts, drag race or drive in the snow. Do I really need a limited-slip diff? Needs and wants differ.

If I were to go the limited slip route I think I would go with a Truetrac as it has no clutches to wear, in fact there be nothing to wear out. 

Can this shade tree mechanic install this with no ill effects? 
 

To answer your question, No. Leave it be and enjoy what you have. Let Alice in Wonderland drive someone else crazy....

You yourself will run out miles before them trac-loc clutches wear out

There’s a lot of truth in Barry, Red, and Bob’s statements. Especially wet corners on exit!!

When I replaced the gears in my case last year, the clutches in the traction lock still showed some life left in them. Don’t know if they’d ever been changed, but the gears still had Ford numbers on them.  I installed new clutches anyway.

The TrueTrac is a good LSD.  I'm about 90% sold on putting one in the rear of my '06 F250 to replace the Yukon clutch style LSD that is just starting to get weak.  They don't have the bad habits of a Detroit, but they don't wear out like a clutch style LSD.  The only detraction I've ever heard was that they take a split second to lockup.  I can see that because they kind of work opposite of a clutch style LSD.  In a clutch style the default setting is locked.  It becomes open when the breakaway torque is exceeded and allows slippage.  The Trutrac's default setting is open.  When power is applied to goes to locked. 

Now, given as much as our Mustangs typically get driven you'll likely never wear out a standard Ford TracLok.  I've seen plenty of them wear out after 50-100k in higher powered applications though.  Somewhere I have some clutches out of my buddy's first gen Lightning that have no friction material left on them in places.