Look into these. I have them on my 2011 3500HD and they work great. They are 5500K and put a lot of light on the road.I went with the poor man's option because I didn't want to modify wiring, etc., and wanted something street legal that plugged right into the existing harnesses and lens housings. I started with silverstar ultras but quickly became annoyed with how they burn out so fast. More recently I tried the new solux bulbs in low-beam, high-beam and fogs. I will say that if you're looking for that harsh white/blue color, these probably are not for you. Solux's claim is that they duplicate natural daylight better than any other bulb and I'd actually agree that that is the exact color they are - they list it at 4600k. I really like them a lot and notice they are much better than standards. Now, their last claim is that they last as long as standard halogens and 2x-4x times longer than silverstar ultras. I've got the invoice in my glovebox and will watch.