[1971 GMC SHORTY]

Originally Posted by EVRLET

I wondered why they yellowed quickly and so I did some low budget experimenting. I have 4 NBS trucks and they all have aftermarket headlamp assemblies. I live in Vegas and so the heat is nice and toasty.

All my trucks had the headlamps with all chrome housing. I’m not talking about just the reflective portion, but the outer edge of the housing too. The factory headlamps are black edged.

My research showed that the all chrome housing started yellowing within the first year. The brand did not matter. Could the reflection be the issue, who knows.

When I switched to a black housing, either all black inside or just the outer edge black, the lens did not yellow. This pic of the black edged housing is 2.5 years old, on a daily driver truck, that’s parked outside 24-7, soaking up the Vegas heat. The all black housing is about 2 years old parked outside 24-7. The yellow headlamp is the all chrome one and is just under 1 year old.

I’m convinced that the all chrome ones yellow more than black housing ones. Maybe I got a good batch or maybe the all chrome one reflected too much and accelerated the yellowing.

I Bought New ACDelco Headlights And Had UV Protection Clear 3M Film Put on And They Still Look New after 5 Years