I have to side with Mike here..........weight and hook are what kills them.
The factory was worried about longevity and heavy footed kids costing them a ton on warranty work or they would not have spent any extra by installing 60's in cars.
They have a good point.
But an 8 3/4 will take a lot if it is set up right.
Back brace , aftermarket cap and axles make them a heck of a lot tougher than how they left the factory.
Not Dana tough , but pretty sturdy.