A-body 8-3/4 housing plus 489 sure-grip center

Except for 1969 , the 489's came with Auburn type cone style. You can buy new Auburns to fit the 489 but you cannot "properly" rebuild a stock cone-type. The 742's came with the Dana Power Lok clutch type diff. These are easier to setup in that they do not use a crush sleeve. The sure grip units themselves will fit all 8 3/4" housings. But the pinion gears don't.
Read this link all the way through to get the real scoop on Mopar diffs. I would also put it in your saved file;.
Mopar Rear Ends / Differentials / Etc