I installed the sequential flasher unit from webeclectric products (
www.webelectricproducts.com/ ) on my 67 convert and drove it around today. they look really neat, I even saw some people pointing at them in my review mirror. they cost $69.00 including shipping. their wiring instructions are apparently meant for a ford or chevy, so I had to do some circuit analysis my self, but once you get it figured out it is pretty simple. it might even extend the life of the turn signal switch a little by reducing the current load by one third in the blinker mode (by lighting only one light at a time). If anybody needs some help installing one , I'd be glad to offer advice.