led tailight bulbs

I replaced mine today with Philips (12899RX2) Red P21/5W LED Exterior Bulb in my 67 barracuda. 4 way flashers work along with turn signals and brake lights, and they are difinatly brighter than before. In the post there was a similar light for back up lights, does anyone have that post or no the part number? I dint need any ballast or fancy flasher to make them work.