The problem I have with the answer given, Is the fact that I DID stop mine from breaking teeth. The problem was after doing that, I started shearing off the pinion shafts. No broken teeth, just clean breaks at the yolk.
I am not advocating the use of an 8 3/4.
I will say, that using the gearing I did compared to most others, combined with the car weight and trans brake, would put much more strain on the pinion shaft, and with more(numerical) gear, would have most likely run back into the tooth failure zone. However, that is not the "case" (pun intended)
I mean no disrespect. Healthy debate. I just go by my experience. Yours may vary...