Our LED marker light replacements are much BRIGHTER...I'd place this project high on one's 'to do' list...
I also converted the tail/stop/BU lights to LEDs - here's how I did it three years ago... http://www.airforums.com/forums/f173...-as-42187.html
Doing the tail/stop conversion today, I'd probably go for the LED-Kit2, mentioned above - it looks like a good way to go, and the price looks good for all the material you get in the kit....IMHO
Make you day brighter, and after dark, too! Go LED - we've now converted ALL our lights to LEDs...so of our other data is shown here: http://www.airforums.com/forums/f173...way-41888.html