It was when the new edge (99-04) came out when they switched to the wider housing. I highly recommend swapping to the 8.8 rear end as it is much stronger and you will have LSD/locking differential. I have a 1999 v6 and i kept on breaking the spider gears so i swapped to a 95 8.8 axle and now my tires it further in. Nothing wheel spacers cant fix though. 98 to 96 rear end should be simple bolt on installation. no extra components needed.