8 3/4" - is it 741, 742 or 489?

duster360 said

Yep, 489 case. That's the one I prefer cause it has the largest pinion. If you pull it to do any work, throw away the crush sleeve and install a crush sleeve eliminator. Click the link below to see it.

http://www.doctordiff.com/8-3-4-489-case-crush-sleeve-eliminator.html

Click to expand...

I talked to Dr. Diff today, that's why I'm trying to identify this.
I'm buying a complete posi differential with 3:55 gears, 4.5" BC axles, and 10" drums setup.

I just couldn't answer him when he asked which housing I had!

Placing my order in the morning! !!!! Woohoo! !!!!!!