I have the 6V kit and had to work on the reflector holes to get the adapters to work. I have never been satisfied with the dim on these as they are way too dim, seems like something is made wrong with the bulbs. I have another set running on a car with 12V and they work fine on bright and dim.
If you can run a sealed beam... I found a 7 in. Halogen on EPay for 25 a pair. 6 volt and they are bright. In yours,you might have to file xtra notches for the bulb to seat and add a wire tie to hold them in. Ken
I have a stock '32 converted to 12 volts. I replaced the stock bulbs with the "Brite" bulbs from Ron Francis, wire-works.com, (800) 292-1940. They go right into the original light sockets and work great.
I have 6 volt halogen bulbs and reflectors in my 32. They are reasonably bright, you just need a real strong generator, or better yet an alternator. I also have a 6 volt electric fan in my 32, cant run the fan and lights together for very long, generator cant keep up. Rich