Got the HID's in today. I must say I do like them. I got the 9006, for lows and fogs. I think Gm knew that HID's would be put in these because there is a perfect spot on the inside of the fender, on the out side of the housing. The ballast squeezes in there perfectly, and there is a bottom on it too, Its like a air tight cubby on both sides. barely squeezed in. The install only took like 45 mins for all of them. here are some pics. edit: I also noticed I use less volts from the gauge. Im a tad over 14 now, before it was a tad under.
http://www.ls1truck.com/upload/files/40/jeffs%20033.jpg
http://www.ls1truck.com/upload/files/40/jeffs%20034.jpg
http://www.ls1truck.com/upload/files/40/jeffs%20032.jpg
http://www.ls1truck.com/upload/files/40/jeffs%20036.jpg
http://www.ls1truck.com/upload/files/40/jeffs%20038.jpg
Brights vs HiD lows.
http://www.ls1truck.com/upload/files/40/jeffs%20039.jpg
http://www.ls1truck.com/upload/files/40/jeffs%20040.jpg
http://www.ls1truck.com/upload/files/40/jeffs%20042.jpg