I have looked into this and have found a better solution than the resistor. One of the main reasons for using led bulbs in the first place is for low energy consumption, which equals more amperage to run other add on electronics.
So you can see why I was against the resistor fix. The resistor is merely taking the energy that was used to produce light in your old incandescent bulb and expelling it as heat, this fools the stock ford flasher into thinkin that an incandescent bulb is being used. In most cars you can go ahead and get a "heavy duty" flasher to replace your stock one, most of these heavy duty flashers are not load sensitive, much like the flasher in our explorers/mountaineers that that flashes the hazard lights. Sadly though in our case, no one makes a "heavy duty" load insensitive flasher for our vehicles.
So the only way to go about things is to get a couple of generic load insensitive flashers from the hardware store and hook them into the 12 volt signal before the stock ford flasher, and simply bypass the stock flasher. This will give us both the benefits of cool led lighting and the low energy consumption.
Oh, and I though that I might recommend the 25 led turn signal bulbs that are found on ebay, they are what I have been using, and they work great! (no smoking, and they use the reflector as well)