H1 H4 Headlight Conversion

Last Updated 09/21/06

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H1 H4 Headlight Conversion
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Upgrading Sharks to use E-Mark or European H1 and H4 headlamps is not as easy as it seems.

You run into a clearance problem with the depth of the assembly and the diameter of the opening in the rear where the wires feed through. The H1 has a housing that extends too deep. You can see this in the pictures. The Shark's opening is less than two inches. The H1 assembly with the rubber cap needs a 2 1/4" to 2 3/8" opening. The headlight buckets where the H1/H4 assemblies mount has no clearance problem. The problem is the aluminum frame behind them.

I ordered 2 Hella H1 Hi beam only and 2 Hella H4 Hi/Lo assemblies from a seller on ebay for about $150. The H4 went in with little difficulty. The stock connector plugs directly onto the bulb. The H1 assembly created the problem. It wouldn't fit. It was too deep. If you are buying H1 or H4 headlamps, look for a long tube attached to the backside. If it is there, it is not going to fit without modification. I see a guy selling lights on eBay saying that they fit Vettes.. From the pictures, I don't think they will without modifications.

Here's a good place to look for lights. This link takes you to the exact models I installed. http://www.rallylights.com/hella/5.75_lo.asp

They also sell relays and wiring harnesses to support higher wattage bulbs. I used standard wattage bulbs. If you want to upgrade to brighter bulbs, look into the amperage requirements. The stock wiring probably won't handle it. You can buy relay kits. You might have to upgrade the alternator to support them too.

I've been studying this problem for months. I knew I had few choices. I tried to find shallow H1 assemblies like my H4's. I only found low quality lights without the European E-Code. I thought about using 4 H4's and just connect the Hi beam on the inboard units. I thought I might run into vehicle inspection problems when I finally ship this car to Spain. The only solution was to open up the hole. This turned out to be a whole lot easier than I expected. I thought I'd be spending hours grinding away. All you need is a hole saw and it's done in minutes!

I bought a 2 3/8" wood / metal hole saw. Don't use anything larger! A larger hole saw will probably break through the small amount of aluminum that remains near the bottom right or left. Breaking it probably won't cause a structural problem but it won't look very good and will leave some very pointed ends.

Start drilling slowly. Try to maintain a small bridge as shown in the photos below. Use the headlight housing as a guide to keep the hole saw on track. I ended up with metal filings everywhere. You might want to address this by using a shop vac to capture the filings as they come loose.

Drill straight back and deep enough to remove some of the support. Clean up the opening with a file.

I also opened up the hole for the H4. It is not required but (a) I like symmetry and (b) maybe a replacement needs a larger opening.



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This site was last updated 08/14/06