Same with an 8.75. One under an early 6 cylinder A-body was weak as water. The hi-po units were much better.
So which 8 3/4 was the better one? 489,741,742?
The 742 is the best stock 8 3/4, the 741 will live very well in a medium weight, medium power BB A body
My 440 powered 1969 Dart GTS weighed 3300 lbs with me in it and had many, many runs on the OEM 741 case and posi with the OEM 3.91 gears. That car went 11.17 at 122 MPH in Las Vageas in November many times the last time I raced it here
The stock 489 case with the crush sleeve is the weakest of the three, the 489 and 741 have the same size pinion gear diameter size at the front bearing
If you put a pinon gear spacer in place of the crush sleeve then it is as good as the 741
The 742 and Dana 60 pinion gear shafts are bigger diameter at the front bearing