Trac-lok question

My 1999 Orvis 4.0 (D30 front and D35 rear) has Trac-lok LSD according to a label in the glove compartment. I want to change the oil in the diffs and know that the LSD needs friction modifier adding. My question is, is it only the rear diff that has Trac-lok of does the front have it too and also require additive? Thanks.

just the rear

You can buy Redline, Royal Purple, and Amsoil gear oils with the additive already in it.