I don't have any experience with a True trac but the Trac-loc came in the Dana 60's I believe somewhere around 1970 and newer and were not that great of a posi, it didn't take alot of torque to break them loose and they wore out fairly quickly. My preference would be a Powr-Lok that the factory used from 1966-1969 and I believe the aftermarket makes them. In all my 8 3/4's I run the Power-Lok posi's (oh the purists will correct me on it being a "Suregrip" and not a "Posi" oops) and they work great and you can set them up fairly tight or looser depending on your preference.

Here is a link to Dr Diff he is a great source for parts.


https://www.doctordiff.com/drivetrain/dana-60/