Maybe the more tenured in this crowd can answer a question for me?
Why is a 9" so much stronger than an 8 3/4"? Many talk about back bracing 8 3/4" rears and someone always says that it is a waste of time yet, to do it on a 9" is okay and not a waste.

For the most part, the two designs are very similar so; why is the 9" so much stronger? Couldn't you just do the same modifications to an 8 3/4" and have a similar result?