If your taillights are the bigger rubber ones you can get 6 volt LED bulbs to fit in them
i used LED on my brake lights on my CMP when it was 6 volt the work on a 2 bulb circuit but not a 4 bulb circuit. It did make them much brighter than the running light.
Now though I switched the battery and the voltage regulator to 12 volt and put LED bulbs in all the lights including the dash lights. I put a pencil light as the running lights on the back and the larger early rubber lights for the break lights, cause I had a pair available at the time.
I was out working on my 20 CWT trailer, all set up and making progress when my wife dropped by and whispered in my ear, "there's water under the hot water tank".....
