In general a sealed bean conversion is a very bad idea. If the bulb is behind the lens the lens will defocus the beam. If it replaces the lens it will look like the eyes of a monster in a late night movie. If you are 12 volts get some "Brite" (their spelling) bulbs from Ron Francis wireworks, (800) 292-1940. I am using them in my '32 and they work great. The bulbs go right into the original sockets. Be sure your reflectors are bright. Have them silver plated or better yet have them aluminum plated by UVIRA, (541) 474-5050. Don't laugh, that is the technology used in medical mirrors and spacecraft where they don't cut corners.
Charlie Stephens