In my late teen's I melted some scrap aluminium Cat pistons and cast and machined some wheel spacers(they were in fashion then) for a mini and also a triumph herald, they worked well too.
Yeh I had some on my cooper 3" long 3/8 unf studs makes me cringe now, though I never lost a wheel,( on the mini anyway) LOADS of wheel bearings though, even the tapered timps.