Wish i knew at what weight kills them as i broke one bout 20 years ago on the street.Tore it apart and it was the spider gears,Went to a spool 33 spline with the street/stripe axles broke an axle,upgraded to a 35 spline/race axles all was good ran with that setup for about 10 years never broke a gear or anything(wish we had a wood knocking icon )but went to a different gear(4.56 to 4.10)which kind of raising my worried factor cause the 4.10 ring gear seems a little thin we shall see.
as i broke one bout 20 years ago 
on the street.Tore it apart and it was the spider gears,Went to a spool 33 spline with the street/stripe axles broke an axle,upgraded to a 35 spline/race axles all was good 
ran with that setup for about 10 years never broke a gear or anything(wish we had a wood knocking icon 
)but went to a different gear(4.56 to 4.10)which kind of raising my worried factor cause the 4.10 ring gear seems a little thin 
we shall see.