warp2diesel wrote:
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H4 bulbs do not have the sealing rings and can let in dirt, dust and debris, I would look for bulbs that drop in and work like 9007s.
Watts and candle power is what counts, shop for that.
The Carello retrofit headlights I got for my Challenger had a large rubber cup/boot that sealed against the back of the headlight housing and around the three prongs of the H4 bulb. I put dielectric grease at both locations. No problems with air/water/dirt infiltration. Of course I wasn't offroading the Challenger, and the headlights only got underwater once (no water got in though). The Hella retrofit units also had a rubber boot.
Perhaps those boots can be located separately if H4 units end up being used.