Headlights 78 Firebird Formula

Anastasiofan92

Newly Enlightened
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Dec 15, 2009
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Ok guys, so in the past year I've fully restored my 78 Firebird, but I've got a question for the experts. I installed a full set of four H4 assemblies to replace the old sealed beam models. Well, the stock harness for the center hi beams accepts a two prong bulb only while the outer lights use a 3 prong. So the H4 bulb works with the outer lamps, but obviously not with the center sockets. Could I use H7 bulbs for the center to fit into the stock two prong socket? By the way, I'm having a new stock engine/forward lamp harness being built now to replace my old one that's been hacked up. In the new harness I'm having relays built into the headlamp harness to power aftermarket headlight setups, but for now I just need to know if I can run H7 bulbs in the center hi beam locations to go with the two prong socket for when I install the new harness. The center lamps are the hi's and the outer two are the low beams so I need to figure this out. Thanks guys, Kevin Martin
 
Ok guys, so in the past year I've fully restored my 78 Firebird, but I've got a question for the experts. I installed a full set of four H4 assemblies to replace the old sealed beam models.

Oops...that's an error. With a system of four small rectangular lamps like yours, the high beam setting of the H4 lamp provides the close-range light, and you're supposed to have a single-filament (usually H1) high-beam-only lamp to provide the distance throw. Which exact H4 assemblies did you install? There's a lot of junk on the market...of course it's all sold as "upgrades" 'cause you sell more lights claiming your stuff is an upgrade than admitting it's junk! ;-)

Could I use H7 bulbs for the center to fit into the stock two prong socket?

Not unless you were to find a (nonexistent, TTBOMK) 6½" x 4" high beam headlamp that takes an H7 bulb. Each headlamp is designed to accept only one kind of bulb. You can't just toss in whatever kind of bulb you want; only the one kind fits and works in any given lamp.

You might want to go see what Stern has, maybe there is an H7 high beam I'm not aware of, but I know for sure there are H1 high beams with the 2-prong connector you need.
 
So I need the H1 4x6 housings for the center hi beams? I've been reading here about it because the Monte Carlo's apparently have the same exact set up.. Anyway, I'm also planning on running HID's on the low beams in the future, probably 6000K, but the relays that are being put into my forward lamp harness should give the harness enough juice going to the ballasts to prevent any flickering issues. Just to let you guys know, I have 4x6 H4 housings by Matrix. They're angel eyes.
 
I'm also planning on running HID's on the low beams in the future, probably 6000K,

Bzzt! Wrong. "HID kits" in halogen-bulb headlamps (any kit, any headlamp, any vehicle) do not work safely or effectively, which is why they are illegal. See http://www.danielsternlighting.com/tech/bulbs/Hid/conversions/conversions.html .

I have 4x6 H4 housings by Matrix. They're angel eyes.

They're off-brand junk. You will never see well with them no matter what bulbs you put in or how you wire them up. If you are actually going to drive at night, get real lights made by a real manufacturer, and leave the angel eyes on BMWs where they belong.
 
All right, so Hella are obviously the best I've heard, but what about those "Xenon" bulbs then? Should I consider those at all? Or what bulb/headlight combination is best for straight up Halogen light output? I'm shooting for the best here, but obviously Xenon conversions are out of the question now. Thanks for your help so far though, I appreciate it.

By the way I'm going to need two H4's and two H1's. Who makes the rectangular H1's I need?
 
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All right, so Hella are obviously the best

Not necessarily. Hellas in that size are pretty good, but Bosch and Cibie both make better lights in that size.

but what about those "Xenon" bulbs then? Should I consider those at all? Or what bulb/headlight combination is best for straight up Halogen light output?

"Xenon" is a much used (and much abused) term in automotive lighting. Go talk to Rallylights or see what Dan Stern recommends...if I were guessing I'd say probably Cibie H4 + H1 and Narva 100w H1 and 100/90w H4 bulbs, but he's got a very interesting beam plot at the bottom of this page of beam plots from headlights in the size your Firebird takes.
 
I called Rally Lights and talked to them, really knowledgeable guys it seems. Cibie's are a bit more than what I'd like to spend, so I think I'm going to go with the Hellas with the stock bulbs for now. I'm going to see how I like them and possibly upgrade the bulbs at a later time.
 
That's a reasonable way to go. Make sure you get the Hellas with the optical cuts and facets in the lens, not their "FF" clear lens unit. The FF isn't as good a performer, has no bulb shield (and needs one) and its reflector is made out of thermoplastic which limits the bulb wattage you can use.
 
It's thermoplastic. No matter what Hella or Cibie claim, you can't run high wattage bulbs without burning the reflectors. I found this out after running 100w and 130w, briefly, bulbs in my Oscar SC.
FF reflectors need to be fairly big to get a decent beam patterns. In a light as small as 4x6 this isn't going to happen. As has been said, Hella are good starting points for lights, most people think they are the top but I prefer to use them as the entry level then move up to Cibie. Avoid IPF and Stanley brand 4x6, if available for right hand traffic, as my experience isn't that positive.
 
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