7 1/4 rear strength

The spiders shatter from shock or the cross pin seizes from peglegging. The latter you can install a SureGrip to avoid.
But as to the shocking, autos are waaaay easier on the spiders,cuz you don't shock them the same as dropping the clutch. And the bigger your tire footprint the harder the hit.And the more side gear lash you have, you're just asking for trouble so NO J-hooks.
I blew one up with slanty,big tires, and a 2800TC. And I have driven hard with a 340 auto, and skinnies, for several years, and destroyed the 904 first.. Lucky me I got to learn 904s.