Probably, but I suspect it would be rather expensive. The FFV vehicles have an octane sensor to adjust the ECU for gasoline or E85 and you would probably need a new ECU. The ECU may be the biggest problem since the 2004 (FFV's) use a different instrument panel with a text message area. You would probably need a ECU from a FFV 2003 Sport Trac.
I suspect there may be other control devices that would need to be changed as well as some, or all the fuel system components. If you can find an 2003 FFV Sport Trac in a junk yard and good buy all the engine controls, ECU and fuel system that would be the easiest way but it would still be pretty darn expensive just to save a few cents a gallon and get less MPG.
If E85 production ever gets big enough to overcome gasoline, I'm sure there will be many companies selling both universal and custom conversion kits. Since that is not likely to happen for at least 5 years and by then most people would start looking for a newer FFV that may even run on 100% ethanol??
...Rich
