Which is stronger

If you have the parts, build the 9.25 it is one of mopars rears that I have not been able to break.
I have blew 8.75 out with a slant six, one owner car gave to me by my grandpa.

Beat a stock 9.25 hard in this Ram charger running 44" tires and a 4-speed, no issues.
Probably more stress on that rear jumping around in the mud, rocks than a street car would see, plus I wheeled in 2wd most of the time.