Those are known as "city lights", it's an European thing to increase your visibility to other drivers while driving in urban environment where overhead lighting may be good enough to where you don't need to run your actual low beams. So yes, more or less like DRLs, only weaker. If you were doing the H4 Euro headlamp conversion instead of LEDs you could order your new lenses with that option for only a few bucks extra. We did not do so for our MDT as there was very little motivation to cut into its factory 5x7 buckets to make clearance for the city light bulbs, in hindsight we probably should have though, for DRL purposes. Ah well, maybe down the road.
That is the same issue we ran into as well, I also have a friend there who will ship them no problem if she finds them, but for years she has had zero luck with that... Well other than those on her own truck, but she's not letting go of them, ever (she drove that point in loud and clear)
Finally broke down and found another solution that involved US parts, so if anyone happens to run into a SoCal bricknose truck with 4 round lights like an early '70s GMC, yeah, about those... 
Quite a bit more work involved that way though, but if that's all we can get then that's what we gotta do, right?
Those are known as "city lights", it's an European thing to increase your visibility to other drivers while driving in urban environment where overhead lighting may be good enough to where you don't need to run your actual low beams. So yes, more or less like DRLs, only weaker. If you were doing the H4 Euro headlamp conversion instead of LEDs you could order your new lenses with that option for only a few bucks extra. We did not do so for our MDT as there was very little motivation to cut into its factory 5x7 buckets to make clearance for the city light bulbs, in hindsight we probably should have though, for DRL purposes. Ah well, maybe down the road.
That is the same issue we ran into as well, I also have a friend there who will ship them no problem if she finds them, but for years she has had zero luck with that... Well other than those on her own truck, but she's not letting go of them, ever (she drove that point in loud and clear)
What he said. With the help of members on here and a few friends, I did some rather in-depth research on this, and found that it isn't really a practical option. I'm really not a fan of the brick-nose headlights; with the lack of aftermarket options out there, I was hoping this would be a viable route...unfortunately, the only real choices are to switch front clips or to get creative with fabrication.
I don't know what light pattern the LED's will put out, but I really love the H4 drop-in replacements for the sealed-beams I have on my slant-nost That's cause it was a one-off deal, nothing the factory ever offered for these trucks. The inspiration were the new Mustangs, which you can have with an optional pair of giant driving lights in the grille. It was done with factory '70s F-series headlight buckets IIRC, been a while now. Those can be had for both round and square lights, so there are options there... or one could mix and match, for example square lo-hi outers and round fog or spot beam inners. Really anything is possible with a welder and decent imagination
Someone on here had a pair of the square buckets installed inboard of the factory square ones on a '80-'86 truck after cutting the grille accordingly, IIRC they switched their factory lamps to H4 Euros (like the Warden has done) and the new inners were some HID stuff that's highly illegal for on-road use but they didn't care cause it was on a separate circuit and all they used it for was lighting up fields and stuff.I remember seeing that mentioned before. Don't recall if it was a problem with the 1st gen TruckLites, or all TruckLites (they are on V2 or V3 by now). Another LED manufacturer, likely JW Speaker, did not do that. Peterson also has LEDs now that are supposedly very good. And there's yet another name in the game, Nolden. So what I'm getting at is, if you're not 100% happy with the TruckLites as far as operation goes, you have other options as well. Oh, and another thing, did you check how much these LEDs stick out forward? One of the aforementioned ones, don't recall which one, sticks out quite a bit more than the sealed beams, which in your configuration could result in hitting the plastic headlight surrounds and a need to trim them down some. Which would be rather unfortunate considering how rare they are to come by. Just a heads-up, if you haven't check that dimension just yet.
Uhm, no! Those things look retarded, completely out of place on a truck that shape. Well that's my opinion anyways, plus the better half said she'll disown me (or worse) if I ever consider even considering (her words! lol) installing a pair of these on any of our trucks. I'll stick to OBS aero mirrors and west-coast or factory-tow full-size...
