Got his mod done a few months ago. I got them from superbrightleds.com. They have a specification sheet for each one of their different types of LEDs. I just matched the back of the bulb holder/socket to the specs of the LEDs they have listed. Took about two hous and a good caliper. I took my time so wouldn't order the wrong one. Got them in less then a week. Everything fitted perfectly and didn't spend more then what I needed. Good luck.