I replaced all of my interior and exterior (except for headlights) filament bulbs with LEDs from HiPo parts. They have a complete list of their LED bulbs for 69-70 Mustangs/Shelby's at https://www.hipoparts.com/1969-70-ford-mustang/. Their flasher, however, didn't work for me. I ended up using the Bespokepower BSP-FLSH 1.