A little while ago I made a clutch housing from 7075 aluminium to replace a standard cast iron specimen.
This one from aluminum was calculated at up to 14,000 rpm. for an 80cc mopet racer.
And although the aluminum 7075 was much stronger than cast iron, it was not wear-resistant at all. I was able to drive 180 miles with it and then it was worn out, while the cast iron one had already gone over 10,000 miles and stil going strong.
So it is really important to pay attention to how you use it and for which application you use it.
Strength doesn't say everything.
I think the front axle should be tested for shearing to.