Mr. Merk
Newly Enlightened
That would be these Valeo-Sylvania HID headlamp assemblies, properly engineered as HID headlamps. Second preference would be the halogen version, which has a bulb shield and uses an H11 low beam bulb rather than 9006 -- the H11 produces 350 lumens more than the 9006, and has better filament precision. Another poster pointed you at these lamps via SUVlights. In this particular case, he pointed you at a legitimate product from a disreputable vendor worth avoiding (factory rejects sold as "second generation improved" lamps, etc.). Better to get the lamps directly from the maker, even if it costs a few bucks more, thereby avoiding SUVlights' scummy business practices and avoiding any warranty "issues".
The links are no longer working from this post. I have a co-worker with a GMT800 Z71 Tahoe that was inquiring about headlights today. What is the latest and greatest for these models?