Cheap, is reletive. What is cheap for you may be too much for the next guy.
Least expensive, remove some of the leafs in the springs. The next step up would be monos or duel leaf springs, or lowering springs, starting at about $400 an axle.
If you are a good fabricator, you could probably clip it for less, that is if you had a good "cheap" source for your clip. You would still have to do something to the rear to lower it. Fliping the rear axle will lower the rear about 5 to 6 inches. I don't remember the frame clearence on the 59, so that could be a problem.
With good engineering anything can be overcome.
