Yeah, yeah, I know, these are "traditional on hot rods since the '90s." Still, I think they're a cool piece of streamline design. I've heard that the earliest, pre-1940 units used a bulb-and-reflector setup with a lens and trim ring shared with the 1937-'38 Chevy. I've never seen such a setup, but I'd like to. I also understand there are early and late marker light lenses. I'd love to know when that change occurred. Maybe this has been covered before? If so, don't hesitate to point me at the thread. Thanks!
This website has a good overview of the Guide / BLC headlights. http://www.hotroddisorder.com/2013/01/guide-to-blc-headlights.html
Thanks for that, chickenridgerods! Definitely some good information there, but sadly no dates or chronology on the changes and very little about the early bulb-and-reflector units. Anybody else?
I’ve never seen a Guide light with a separate reflector, bulb, and lense. I always thought they were created when sealed beams were created.
I was trying to find the same information. Just restored mine, it has the top version of the marker light shown in the link above. The shell had been re-drilled to take sealed beam units at some point. I also installed halogen bulbs to turn the marker light into turn signals without modifying the bulb holder.
I've never seen any that did not use a seal beam bulb. Maybe that idea came from the early seal beam bulbs that used a metal housing, an internal bulb, and a glass lens crimped on the front. There are two styles of marker light housing; one with a smaller opening for the lens and one with a larger opening. There are two styles of marker light lenses, one rounded and one pointy. Some lights have tags and some don't; but may be stamped on the bottom. OTB makes nice rings, bulb retainers, and pointy lenses (wish they made round ones instead) that fit original lights.
That's because Harley used Guide lights, as did numerous other vehicle manufacturers. Guide used a common ring for the various housing depths since the lamp itself doesn't change. Nice find on the alternative source. It looks like the Harley ones are from Wyatt Gatling, although I bet they're from the same manufacturer as the ones sold by OTB since the price is pretty similar. https://www2.vtwinmfg.com/classic_pre_1984/lighting/headlamp/rims.html.html
FYI .. If you want to use the marker light as a turnsignal this is the bulb to use. Fits the stock bulb holder.
If you need the trim rings, buy the OTB rings, and not the cheaper ones on ebay like I did. The stamping for the screw and its threaded partner are too big and do not allow the ring to close up tight to the bulb retainer leaving an ugly gap at the bottom.
I got cheap ones one time, you just need to trim the bracket back slightly. The better quality ones don't need this mod.