That is a sweet car. You should try also posting this in the General Discussion section or the Big Block section.
I find that these cars are pretty close to dragging over speed bumps as they are stock. You probably already have 1" or 2" of spring sag just from 50+ year old springs. Drive it a few weeks to make sure you don't have dragging issues now at your favorite places. The wheel base on these cars is long and it doesn't take much of a steep driveway transition to scrape.
You can try lowering springs or lower profile tires. You can put on those bolt on spring compressors for "lowering" cars just to try out the stance and clearance. I don't recommend them for long term. Changing your spring height and spring rate leads to a harsher ride. I don't recommend heating and cutting the spring coils either, that could lead to bottoming out, which can be dangerous.
Another way is to go to a full air bag suspension. Then you can adjust to any height you want with an onboard compressor.