Several years ago I got tired of the dim factory halogen bulbs in my 2012 3500HD. After a lot of research on LED replacement bulbs I bought my LED bulbs from GTR lighting. They are not generic replacement bulbs. They are a high end custom designed bulbs to produce correct bean pattern and they are incredible bright. They are 220.00 a pair and come with a life time warranty.
I first installed the low beams about 3-4 years ago. I couldn't believe the bright white light these bulbs produced. They illuminated the road like daylight. But you must check the alignment of your headlight after installation. I had to re-adjust my headlights. There are videos on YouTube to show you how to measure and adjust them. I was so impressed with these bulbs that I replaced my High beams and fog light.
About a year ago one of my low beam bulbs failed. I contacted the company for a replacement under the lifetime warranty. My bulbs where no longer being produced because they came out with a newer upgraded bulb. So they sent me a pair of their new Ultra 2.0 bulbs under warranty no problem. If you are looking for high quality replacement LED bulbs and that come with a lifetime warranty I highly recommend GTR lighting. They are the last bulbs you will ever buy. Just remember you must check and adjust your headlight after installation so you don't blind other drivers...Here's the link:
https://www.gtrlighting.com