To the OP, I don't know of any drop-in LED replacement for H4/H3 that works properly in a conventional headlight. I went through this last year with my MKIV Golf. After hours of research and reading posts by folks who tried to use the LEDs in the stock VW housing, I finally opted for a projector retrofit (that I am very happy with).


tjts1, who is making projector retrofit kits like that for a W123?


For better lighting, I put a pair of e-code hella replacements in my former W123. Definitely worth the price and the improvement in visibility was stunning: Hella E-Code H4 Headlights - PAIR


There are 7" round drop in projectors made by Truck Tek. But I don't have any personal experience with them. They will look out of place on a W123 imo. https://www.truck-tek.com/Truck-Tek-Accessories-Wholesale-Catalog/index.php?id_product=78&controller=product

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1991 300D 2.5 "Rocinante"
2002 Golf TDI "Teen Spirit"
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1984 300D
1966 Mustang I6 3sp
1985 Mazda RX-7 GSLSE
1982 Toyota Supra
1977 Datsun 280z
1971 Datsun 240z