There are lots of great headlamp coversions out right now. I carry the APC, Toucan, Hella and Pilot conversions for the 67-72 trucks. I also carry the new HID H4 bulbs. They are available in high watt or standard watt versions.
Click here
http://www.carolinaclassictrucks.com/lighting.htm
and go to headlamp coversions to see our products.
I personally have the APC headlamps with the Toucan H4 80/100 watt HID bulbs.
All of the conversions offer better lighting than standard halogen sealed beam headlights.