8 1/4 strength

the pinion stem diameter in an 8 1/4 is 1 5/8" so that is actually larger diameter than the 741 cased 8 3/4 which has a 1 3/8"

I would definitely use it even behind a 383 and I wouldn't hesitate to pound on it either. I have found through personal experience that an 8 1/4 is one tough guy. I have yet to hear of anyone breaking one in real life. You always hear of people breaking them in their car fantasies yet no one ever produces evidence of a broken rear end.

I think the 8 1/4 was an asset to Chrysler and there was good reason they were used so extensively over a long period of time, even Jeep used them.