I am not an electrical engineer by day but reversing polarity on a light bulb should have the same results.
Just to clarify, my reference to mustangs was just that, a reference. There are a lot of fanatics out there for them so there is a lot of information that is able to be applied towards our Eagles.
As for the LED bulbs, buy the correct LED bulb style and put it in. It works on an 82 Eagle I know that. Watch the tail lights cause I dropped the bulb into the housing which is not fun to try and get out. If you get a fast blink issue, Google research it.
My car is equipped with ~65amp alternator. With my 4 channel amp for the speakers and all the standard equipped stuff it is pushing total amp draw. That was my main reason for the swith over to LED.