[vertigto]

Originally Posted by Spaceman Spiff

I used hella H4 conversion housings, then bought leds. Plug and play. I keep a spare set of regular h4 bulbs in the car, Incase one goes out. Easy change.

Is this the housing you went with?

https://www.summitracing.com/parts/hla-002850001

Any issue with the depth (i.e., modifications required to mount)?

Any LED will fit the housing?

[Spaceman Spiff]

Originally Posted by vertigto

Is this the housing you went with?

https://www.summitracing.com/parts/hla-002850001

Any issue with the depth (i.e., modifications required to mount)?

Any LED will fit the housing?

Hella 002850811 Is what I used.
I got the leds from amazon.
https://www.amazon.com/gp/aw/d/B08KY...b_b_asin_title
The first the housing with no issue.
There are two wire clips that hold the bulb to the housing, you just have to play with them a little to get them to snap into place, as the led is a little bit larger body than the standard bulb.

[joelau27]

I was in the same situation with my car, thinking halogen bulbs were good enough. But then I read up on LEDs and changed my mind. Here's why:

LEDs save more energy, so they're kinder to your car's battery, mainly if you use extra lights or forget to turn them off. They're tough and can handle when the power in your car goes up and down, and they last way longer than halogens. You won't have to change them as often, which is excellent. They're also brighter, which makes driving at night safer and more accessible. Plus, you can choose the kind of light you like best. And they turn on full brightness right away, which is convenient.

[Red80TA]

Safer for who? Not the poor pricks you are blinding.

[VCho455]

For the purpose of my opinions on this subject, I am going to only talk about the T-3 style or the H4651 style headlights as we are on the vintage Pontiac forum. Those bulbs were not originally engineered for LED’s and the basic differences in how light is physically produced by the components are very different and pose some difficult challenges when making retrofit headlights that need to conform to preexisting housings. Due to poor engineering, many times the light output provided by these retrofit lights will be so poor the lights are unusable from a safety standpoint even though they may be bright. Add in the large amount of misdirected light that is emitted annoying other drivers. For proof just look at the large number of Jeeps out there with aftermarket headlights that blind every driver they meet. And amazingly all of those light come straight from China with DOT cast into the lenses.

There are some statements here that need further investigation. First off unless you forget to turn your lights off when the engine is not running there is no “kinder to your car’s battery”. When the engine is running the battery is floating at the voltage the alternator is running at. The correct way to statement would be kinder to the alternator. But that may not be entirely true. Many aftermarket LED bulbs have cooling fans and those are generally not included in the power usage listed in the advertising. And as those cooling fans wear out and slow the total power used by the bulb will increase. So the power saving may not be what you believe it is. For our vehicles it's really not that important as most of us are not reengineering our wiring harness to use smaller wiring like the OE's are with new cars.

A pair of 55w halogen bulbs will generally draw 9.5 amps and most LEDs are considered to draw half that. But once again that is an on-paper comparison to show LED’s in at their best. Unfortunately, some bulbs don’t include all the LED’s installed or the cooling fans (If installed) in their advertised wattage. Many do not publish the power usage or a truly accurate and comparable light output.

LED bulbs run cooler which is good unless you’re driving in freezing wet weather conditions then snow and water will freeze on the bulb and significantly reduce the light output just when you need it most.
Which leads to another downside of most LED’s and that is they are plastic. We all know how plastic lenses degrade from UV exposure, from being sandblasted by debris in the air when driving and scratches after having to scrape frozen snow and water off them.

So, while the LED itself may have a longer life the housing, voltage regulator, and fans have a far shorter life span. I may have had to replace the H-4 bulbs in my lights every 30-40 thousand miles but after more than 150k miles my halogen lights are still working as good as the day I installed them in 1997. Photo below of my Burban with its 26+ year old headlights still getting me to work and back everyday.

And a note on the voltage regulators inside of the LED bulb. If your vehicle has an alternator failure and now is only putting our 9 or 10 volts it is highly likely that your LED headlights will not work. No limping home with dim lights and everything turned off that can be turned off. You be on the back of a wrecker for that trip home.

Let’s talk brightness for a minute. Literally all LED’s claim to be brighter than factory bulbs but is that brightness even across the road in front of you or is it concentrated in one very bright spot leaving the areas around it dark, dark like a black hole. One part of this subject is how the human eye responds to light. Once the eyes are focused on a bright area the eye adjusts to that and when you look away to a darker spot your eyes will take time to readjust to that spot but, if it the dark spot is too close to the bright spot a human eye will only open the iris so much leaving that dark area invisible to you. Because LED conversion headlights have a difficult time creating the even wide pattern that you get from quality incandescent or halogen bulbs, they have created their own version of what a good beam pattern should be usually involving some sort of “Hot Spot” in the beam as a good quality. Unfortunately, human eyes don’t agree with the marketing. And in my world the deer and the joggers are always standing outside of the “Hot Spot” making them difficult to see.

There are some quality LED’s out there that have decent beam patterns and have the over hyped “Good cutoff line”. The problem with these very bright lights is the area below the cutoff is blinding bright to other drivers and if we all lived in a perfectly flat world it would be fine but unfortunately, we don’t so every time you crest a hill, you’re exposing the very bright area of your lights to oncoming traffic. This means the driver of the oncoming car is suddenly hit by your bright lights and may lose track of where they are positioned on the road and drift off the road or worse yet collide with you. Add to that situation that the other driver may be so pissed by your extremely bright lights they may decide to bright you. Now both driver’s eyes have been compromised by blinding light.

I haven’t gotten into the discussion about light colors. I will only say is true that the pure white light emitted by HID style lights is very nice in prefect weather but when the rain and snow start to fall that pure white light is reflected by the precipitation and the resulting glare makes driving more difficult whereas a yellower light doesn’t have this effect. This is more of a choice you make in response to the type of driving you expect to be doing with the vehicle. For more information on bulb color see this link,

https://www.danielsternlighting.com/...ght_color.html

The bulb turn on time between Incandescent, halogen and LED’s are virtually the same with the HID type lights having a longer warm up period. HID’s are not even part of this discussion as there is not enough room for a safe, quality HID light to be engineered in space provided by the factory T-3 and H4651 style headlights.

The basic question is are you willing to fork over the $400 to $800 dollars that good quality, safe LED lights cost? And are you willing to accept the shorter lifespan that those lights have compared with quality halogen headlights like a Koito, Hella or Cibie? That decision should be based on driving style, vehicle usage, and safety. Not on price or appearance.

As always these are my opinions and along with $10 they will get you a steaming hot cup of Joe just about anywhere.