you can get kits or new drictional light assy. from http://www.chevyduty.com/

Or run the drictional wire to original front parking light (single bulb unit) and rear original driction light (single bulb unit ) , keeping tail and brake units seperate. then you can use the old drictional light switch
have fun Bill


Bill 1951 3/4 ton 5 window pick up
1955 GMC 1/2 ton longbed automatic