Is a 7.25 rear strong enough?

In an open diff 7.25 the spiders seem to be the weak link.
What is the weak link in the 7.25 sure grip units? Would it be the ring and pinion or axles?
If someone was teetering on the low HP scale they could possibly gain a little strength with the sure grip.
I have never killed or witnessed the failure of the 7.25 sure grip units as I do not think there were many made.
It is a bummer about the lack of 8 3/4 units around. I am glad I swapped mine out when they were still plentiful. One of my a body 8 3/4 rear ends came from a U pull it wrecking yard. The cost was like $50.00 plus $5. 00 core.
When swapping to another rear finding a donor with disks would be a bonus.