Relays, which he is already planning on doing, will not provide much "more usable light". They will simply help insure the lamps get sufficient voltage and current to operate at their best. They will also take a big load off of the rest of the wiring.

The problem with the ole sealed beam, whether incandecent or halogen, is twofold. They are not terribly efficient and second the lamps throw too much of their light in the wrong places. The halogen versions are a bit more efficient, and some brands do a slightly better job in getting the light on the road. The various halogen bulbs (such as the H4) are far more efficient in terms of converting electricity to light. Dan Stern has a chart of the lumens on his website.

The H4 lamps made by companies like Cibie and Hella put the light onto the road because of the reflector and lens designs. They could do this years ago because of Euro and UK lighting standards.* In more recent years Hella has made a US DOT compliant version of the lamps. I've used them, as well as regular Hella's H4s (which were not DOT compliant except for motorcycles) and the DOT version had slightly less jump in hieght between the high and low beams. The Cibie H4s seem to be just as good or better in tems of hi/low placement. However they are in my Jeep which sits a little higher than my Barracuda, so not a perfect comparison.

A few years ago I had the uh opportunity to use a truck that still had sealed beam headlamps (US gummyment contract pennypinching I suppose). I had forgotten just how bad they were. As soon as I had a chance I donated the Jeep's old halogen sealed beams. Not great, but a heck of lot better.

*As early as 1967, Chrysler engineer Scott Harvey was promoting H4s for rallying. "Several makes of European headlights have a very flat, top cut-off on both beams. These lights are as good in snow or fog as any fog lights I have used. Also they have a relatively low current-draw, so their bulbs have quite a long life. They are not sealed beam, so they continue to function even if the lens is cracked." "Scott Harvey and Rally Preparation" in Sports Car Graphic (May 1967) p. 70