8.75 in a 72 dart question

Gimme me some ideas here, stock rear in a 72 Dart (originally a /6), the previous owner put an 8 3/4 rear in it, has 3.23's in it. But no sure grip.

What is the scenario for adding sure grip guys?

First pick the one/kind you want (cone, clutch, etc). The eaton true trac is a good one as well then It's install time. What center section to you have (741, 742 or 489)?