I know it's been discussed here but my searches haven't found the topic. But early e-bodies out of one particular factory seem to sit lower on one side than the other - something to do with the front sprng hanger body mount(?). I've seen more than 1 70 Challenger like this so I know it's not unique to one particular specific car. What was the actual issue (bad hanger hole stamping, bad assembly/alignment?) and what's the fix.

I have 7 Challengers; 5 70s and 2 71s - 6 from Hamtramck, 1 from LA

Never heard of this issue

Same here... I've parted over 300 E bodies over the decades, have owned MANY over the decades, still have several, the only time the suspension may be "lopsided" is when the torsion bars have been poorly adjusted

That, or SS springs. My stock/unmolested '70 Barracuda 318 car sat just fine.

SS springs or people who don't know how to adjust ride height on their torsion bars.