This is something I've thought alot about doing to my truck but haven't gotten that far. I did see this setup on a truck at a show the other day. This guy just added a momentary switch on a bracket to his 3 speed shiftbox to kick his on when he was in reverse, can't think of why I didn't think of that.
[img]http://www.mongosgarage.com/tech/mongo/backuplights/100_2219s.jpg[/img]

Course now I don't have the 3 speed anymore and my new tranny has a hookup for it and I still haven't done it.

Here his backup lights.
[img]http://www.mongosgarage.com/tech/mongo/backuplights/100_2220s.jpg[/img]

Good luck let us know how it turns out.
MONGO


Mongo's Garage
Vintage GM Truck's & Parts
https://mongosgarage.com