I haven't sat down and counted the runs, but my Chrysler 8 3/4 gears have been lasting longer with cryo and REM surface finish treatments. I've had them done at Evans Performance near Atlanta.
http://www.evansperformance.com/
There was an article years ago showing that a 12 bolt was the most efficient differential. A Dana 60 is more efficient than an 8 3/4" which helps compensate for the weight and a Ford 9" is one of, if not the worst for efficiency.The pinion to ring gear relationship has a lot to do with the efficiency ratings.