The thing is, most of these kits are simply HID bulbs that plug into the oem headlight socket with a ballast to power the bulb mounted nearby.
The problem is is that oem halogen headlight reflectors are NOT designed to handle that kind of lumens that HID bulbs put out, and instead scattter them EVERYWHERE, including into the eyes of oncoming drivers.
HID lights are meant to ONLY use projector type reflectors and lenses that precisely FOCUS the bright light onto the road where it belongs.
It IS possible to buy aftermarket projector lenses powered by HID bulbs and ballasts, and retrofit them into your oem headlight housings, so that you can have a stock looking truck while gaining HID lights that work effectively and do NOT blind oncoming drivers. While these retrofits are still not legal in Cali and many other states, they are much harder to detect and since they don't bother people after they correctly and cafrefull installed and adjusted, other drivers or Johnny Law, likley won't notice or complain.
Take a look at this thread--
https://www.turbodieselregister.com/forums/showthread.php?191334-How-to-HID&highlight=hid