Have been to the Techno Classica Fair in Essen yesterday and found a guy with LED bulbs fitted on original sockets, for 6 and 12 Volts. The LEDs were arranged to form the same contour as a bulb. I didn?t like the blue shine of the"white"  LEDs, but I think this is a beginning. Now, other whites are on the market and probably will glow nicer.  Maybe You can find a US source for these too. For me, the spherical arrangement would not have satisfied my safty thoughts. It would have let too much of the available area LED- free.

   btw: the continent?s leading fair showed hundreds of Pebble Beach quality cars , many hundreds of unrestored or long ago restored cars, parts and services. Only approx. 40 US cars don display, among them less than a dozen on sale. Only 2 Mopars.

Greezings! Go

 :) Last season when I rebuilt my stop and turn signals .. I wanted a brighter looking light... I found a guy on eBay from the Chicago area that makes and sells new  6 volt light bulbs called twice as bright.. they truly are brighter ... when he sold them to me he did say they will not last as long as the reg. bulbs .. but for me so far not one problem ..

I bought some dual halogen lamp fixtures for my 46.  I used a set for a 39 Chevy as it allowed both bulbs to fit into the ho,e of the original fixture.  I got them from Juliano's rod shop.  they use a 35W bulb for running lights and 55W for stop lamps.  I did run them with the signal circuit for a while with incandecents in the front.  They did fine except at idle (especially with the brakes and headlamps on)  I rewired my directionals to a coupe stalk lamps from a motorcycle running extra bright 6V bulbs.  So I run 2 running lamps 3 brake lamps and seperate signals.  I need to deal with one of my fronts as it is gitting a little dim on signal, likely from a deteriorating ground.

I put LED, s in the rear brake lights. Low glowing bulbs were unsafe. I had to divide the light chamber for rear lights vs. brake/directional lights to get a german car registration permit.
I had to put a voltage regulator taking 5 to 8 Volts while giving 3.5 Volts . All fitted into one half of the chamber of my P 23 1951.
Directional flasher didn?t work because of low current draw (same effect as with one burned bulb). So I had to put a pair of bulbs in parallel to the rear LED?s near the directional switch. I have bright light on my shoes now while braking or flashing.

After 2 weekends: works perfectly.  Grreetings! Go

I have been told that the halogens get hotter than regular bulbs.  They will do fine in the large  headlights but it is not advisable to use them in the taillights.  LEDs might be better for the taillights.

Just know that they should not be used with plastic lenses. Plastic will discolor, and possibly melt. Life of the bulb with glass lens can be shortened because of heat too. Bulbs are a bit costly to burn up for the difference that I have noticed.

Just for info I was chatting with a seller of halogen light bulbs in Hereshey last fall. I was thinking they might be nice for the tails lights and parking lights i use in my 49 and 40 Plymouths as directionals. He told me they would cause the flasher to not work . Said they could be use but only in the front or rears not both. Anyone know anything about this?