It kind of depends on a few things like tire width and diameter, and wheel offset. Mines' pretty low and I've never had a problem w rubbing. That's with a 245/60 15" tire on a 15x7 rim. It used to sit lower but I raised it back up an inch or so, not because anything rubbed, but because A) you lose some of the effectivness of your torsion bars when you take tension out of em. And B) unlike the older cars our later B bodies don't have an eccentric in the upper control arm to push the top of the tire out resulting in excessive camber. It not only looks goofy, its bad for your tires too.
It's not the definitive answer you're looking for, but I can put a tape measure to my 76 and tell you where it sits now if that'll help. It's probably 2" or so lower than stock, ballpark.
To paraphrase Nike....Just DROP it! An inch won't hurt nuthin', that's about 8 turns of the adjuster bolt, by the way. Also, if you let it down a little at a time, til you find the height you like, that's way easier than going too far and having to crank it back up....ask me how I know THAT.
I get more compliments on the stance of my car than any other single characteristic. Then again, that's kind of a skewed statistic cuz everything else on the car sucks. :headbang: HA!
sorry, man. i don't do lol.