I know this topic has been covered before, but I might have something constructive to add. I think I've found some good 1157 and 1156 tail light bulbs for Cudas/Challengers. By good, I mean they have: (a) good light overall output, (b) don't need load resistors, (c) light output varies noticeably between the tail lights being on and the brakes being applied, (d) price isn't too exorbitant.
Both bulbs are made by Sylvania and should be readily available. The part number for the 1157 bulb is: 1157R, make sure that the bulb is the Zevo bulb. The part number for the 1156 bulb is: 1156, the color temperature is 6000K. I got mine on Amazon where each pair of LED bulbs cost around $20. You can save some money by not replacing the backup lights (1156 bulbs), but I went ahead and replaced them all. I tried to upload a pic of the packages, but the file size was over 500K.
What I like about these bulbs is that they are "plug and play" and closely mimic the illumination characteristics of the old incandescent bulbs. Next, I'm going to try replacing the front turn signal bulbs and see if the old thermal flasher will still work. If not, I bought a solid-state flasher just in case (CEC Industries EF32RL).
