Pants...
If you're running 12-volts, the easiest switch for your headlights is to get a 12 volt halogen sealed-beam at your local auto store...
Not sure if the number is H6014 (could it be that simple?), but I used these in my '72 C-10 and my '61 Willys pick-up.
I have used both Wagner Power-Beams and Sylvania's versions...both are much brighter than regular 12-volt sealed beams. Unless someone bother to read the lettering molded into the lens, it's very hard to tell they're not OEM.
As for your wiring, '54 trucks were the first year for plastic wiring insulation, and the six-volt wiring ought to be "twice as heavy" as is necessary for 12 volt "watt for watt" upgrade.
I wish they would make a six-volt halogen sealed-beam...
Good luck !
PS: you can also get composite Euro-type headlight envelopes that use the H-4 bulbs, but the ones I've seen so far have a much flatter lens than a traditional PAR-56 glass sealed-beam, and just don't look right in a 1940's-'50s US car/truck...IMHO.
