Youngin Can't Decide

RustyRatRod said
Sure grip is simply the marketing name Chrysler chose for their limited slip differential unit. Posi is Chevy, Trak Lok or Traction Lock is general Ford, although there are aftermarket Traction Locks for other applications. It's all marketing.

This makes more sense. Kind of like in the Vw/Audi world with 4motion and Quattro. Relatively the same thing just different marketing names.