As far as the tail light goes I just pulled my old bulb and wired in 4 each 2.3 volt high output LED's from Radio Shack. With a 220 Ohm resistor and everything wired in series it was a direct replacement. I pulled the reflector and then I soldered everything on a piece of bread board and popped it right in. Wired it up and I have good rear red light that will NEVER burn out at the rate I cycle with the dynamo in use.