It depends on what you are trying to achieve. From the mild drop you described, it sounds like you are wanting a reliable driver. Are you running the stock front bar or a bigger aftermarket one? Regardless is it is stock or aftermarket, the thing to keep in mind, is that you want your rear bar to be smaller than the fron to avoid a pushing effect in hard cornering. There are many options available depending on what you would like to spend. ADDCO makes a 7/8" rear bar for only $120, or you could go the next step higher with a Hotchkis 7/8" rear bar for about $385. Hotchkis also offers a matched front/rear set for around $600. Hellwig has 1-1/8" front and rear bars that are just over $450 for both. Adding a rear sway bar will help with handling and tie your front and rear suspension together, as long as you pick the right components to work together properly. If you have the time to do some extra reading, look up the "Make it handle" thread in this forum.
http://67-72chevytrucks.com/vboard/s...d.php?t=419251 There is some great information in there and explains more than just sway bar selection. Spring rates and shocks can also affect how well a sway bar will be effective in improving ride characteristics. Hope this gives you a good start!