Stop in for a cup of coffee

The reason I say that is because normally companies list a 741/742 locker and a 489 separate
I can’t find anything that indicates that different cases use a different Auburn unit. In fact, the Mancini branded clutch type limited slip specifically stated it fits all three housings.
Mancini says this about the Eaton locker:
“Notes: Fits 2.76-4.56 gear ratios. 742 case requires large carrier bearings.”