Want to lower my 66 Dart

I'd say is all about how much money your willing to spend. You can go the drop spindle route but you will have to purchase them from here http://www.magnumforce.com/store/results.asp?CategoryID=84 or here http://www.performanceonline.com/1962-74-Mopar-A-B-and-E-Body-Drop-Spindles-Set-DS6274/ but if you do that you will have to change to the larger upper ball joint (73 and up UCA) and disc brakes (73 and up also).