I just did a quick search so if you do that you will find tons of information. it is here
http://67-72chevytrucks.com/vboard/s...d.php?t=507368
basically tho is continue to use a "conventional" non HID bulb setup there are several to choose from but then put the relays close to the front of the truck by the head lights, this will give you a full 12-14 volts this makes a huge difference in light output from where you are now. The balist is used in the HID conversions. you will get lots of negative input on a cheap conversion as they are not made correct and usually end up blinding the other drivers and not giving you any additional light since it is not in teh correct housing. do a couple searches and you will find it is best to do the relays and better newer sealed beams.