One of the few times I will agree with Pentalab.
The OEM clutch style diff works poorly and generates a LOT of heat.
We burned up several rear axle seals and bearings before we figured this out in ~2011.
Even with the upgraded carbon disc packs we were killing the clutches in the TractionLok in "ones of days" of track use.
We built a somewhat elaborate diff fluid catch can / vent system to deal with the super hot diff fluid boiling.
We eventually upgraded to a Torsen T-2R diff and all of the diff fluid heat and leaks and spewing went away.
We also dropped a little bit of lap time on certain road courses that had some tight corners. Where we fought wheelspin before the car now hooked up!
We've used the Torsen T-2 and T-2R on several Mustangs but haven't had a chance to try the TruTrac yet (might put one in my shop truck).
On the recommendation of another shop we went with a WaveTrac diff in the 9" Ford rear of this tube framed 69 Camaro, which is running the same 345mm rear Hoosier we ran on the TT3 Mustang.
Hopefully we will get some track data on this car later this year.