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.