8 3/4 rear

breakdown of my chunk

housing - $50 off of ebay painted with new seals
ring and pinon new (3.91 gear) - i think i remember it being $200
install kit - around $100
rebuilt sure grip - $200 from a moparts member
arp sure grip bolts - $50

so add it all up and you get $600 for a brand new rebuilt 489 sure grip chunk with arp bolts.