65/66 tailight/backup light conversion

[90volts]

Hi ,

I am trying to find out if there is a conversion available to turn one of the tail/brake lenses into a backup light. So what i am looking to do is have the 2 outside lenses remain tail/brake lights and the 1 inside lens become a backup light. Ididn't even know where to start looking for something like that. The other choice is to do something custom but then that would probably be beyond me at that point.

Thanks for any help.

Mike