I lowered my '57 Chrysler by just turning down the torsionbars and put 3" lowering blocks under the rearaxle.
With a good set of shocks all around I don't have many problems driving around with it.
I will probably put an extra leaf or 2 in the rear springpacks to stiffen up the springs just a bit.

I've also got a '57 4dr HT Plymouth Belvedere waiting as a project. I will be lowered the same way as most of my cars have been done.
The car has great patina, which I would like to preserve fro the time being...