Gear ratio?

Your 741 should be fine. The most common source of failure is the axle shafts themselves ( and related hardware such as c-clips)in ANY rear ( and all 8 3/4 rears use the same axle diameter). If your concerned ( which you shouldn't be), get some stronger axles from Mancini or another supplier. U- joints fail much more often than anything else! Your pinion gear diameter is a little smaller than that used in the 742 and 489 case, but still is a larger diameter than that of a Ford 9" ! Unless you're gonna run lots of torque (500ft. lbs up) AND huge slicks, you won't have any problem.