Static lowering

[67chevy1]

OK I'm new to this game I had when I was younger a 67 swb with a big block in it with the back end dropped to level. I have read on 1 of the threads on here about static lowering, is that when you clamp the coils together to lower or what. I have restored a couple old tractors, but I'm going tomorrow to look at another 67 swb that is a blank sheet, solid but all apart. I want to lower it just a little and wondering the best way. When I say a little just 2 or 3". I don't like the idea of going over speed bumps and worrying about dragging.