I would hope that most of you discussing these lights have taken a trip to a well stocked auto supply house, like Pep Boys, etc. You'll see that the sealed beam's of yesterday are almost history. Most sealed beams are halogen, bright white. There are a variety available--and all at a fraction of the cost of refitting H4 assemblies. Every time you might have to change the lamp, you get a new reflector. Last time I checked they were about $15 each; some high performance ones maybe $20? That's a lot less than an H4 kit.
Just food for thought before you go and invest in something...