Hey, SoTxBoTi
The back up lights are strictly back up lights.
My tail lights are stock -- you can buy 'em from Chevy Duty same as mine ... plus I just put new lenses in with the blue dots and I love 'em!
My tail lights, and the bed-roll lights, operate as brake lights, park lights and turn signals. I put aluminum foil inside the tail lights and they're as brighta s the hallogen bed-roll lights!