I'll give you an honest answer here since I'm making LED products. The LED's will and are changing the way we look at automotive lighting. The installation of LED products not only provides a an additional safety factor by illuminating faster than an incandescent bulb that is stock in our cars. The front and rear of the challengers and cuda's can be updated to current standards. I have Illumin8s that provides a day time running light as well as the amber turn signal all in one LED array for the fronts. Check them out at
www.globaloverdrive.comAn H4 conversion for the headlights is a great update to rid yourself of the yellow / dim sealed beam stockers. Please note that I am installing the headlight upgrade in my Challenger, so I will post the results here.
LED's are one of those products that you get what you pay for. I your look at LEDtronics all the LED products are rated at 12V and 28V in the same package. Most LED companies overdrive the LED's to 28V's to make them brighter. By over-driving the LED's you shorten the lifespan (I don't have information on how much more that is shortens the lifespan but it is significant.) The key is to find products that work (are brightest) at 12V. There are a ton of products out there and I personally have not found anything good for the side markers. Most products (bulb replacements) have been fair at best. I'm still looking.
I have yet to do a set of 72-74 Cuda tail lights yet. I will though in the very near future since a member of the car club that I'm in is willing to allow me to use his car as the prototype. I keep you posted.
Tony Edler
Illumin8s